Anthropic releases Claude Fable 5 with strict safeguards, sparking backlash from researchers
91 Sources
[1]
Anthropic says these topics are too dangerous to let its Fable 5 model talk about
Anthropic Tuesday publicly released Claude Fable 5, its first "Mythos-class" model that it says surpasses its previous frontier Opus models in overall capabilities. But the model's launch today comes with safeguards designed to prevent it from answering queries on topics like cybersecurity,
[2]
Cybersecurity researchers aren't happy about the guardrails on Anthropic's Fable
Anthropic released its latest model Fable on Tuesday, billing it as a public and limited version of its powerful and much-hyped cybersecurity model Mythos. But not everyone is happy with the restrictions, and a number of cybersecurity researchers and professionals have aired complaints
[3]
Anthropic Walks Back Policy That Could Have 'Sabotaged' AI Researchers Using Claude
The company changed course after researchers spoke out against the policy, which would have covertly limited Claude's ability to develop competing AI models. Anthropic is backtracking on a policy that would have covertly limited competitors from using its new AI model, Claude Fable 5, to develop
[4]
Anthropic's Claude Fable is a version of Mythos the public can access today
Anthropic is bringing its most powerful AI model to the general public for the first time, but it's doing it with guardrails. On Tuesday, the AI firm launched Claude Fable 5, the first publicly available version of its Mythos model. Anthropic says Fable 5 excels at software engineering, knowledge
[5]
Anthropic's Claude Fable 5 Is the First Mythos-Level AI Model You Can Actually Use
AI enthusiasts have been aflutter since rumors first leaked in April about Anthropic's Claude Mythos Preview -- an AI model that the company claimed could sniff out so many cybersecurity vulnerabilities that, left unchecked, could break the internet. That's why Anthropic has slow-rolled its
[6]
Anthropic Offers Mythos Upgrade for Cyber Partners and a 'Safe' Version for the Rest of You
Anthropic released two new AI models called Claude Fable 5 and Claude Mythos 5 on Tuesday, which the company says have greater capabilities than the Mythos Preview model it released in April to a limited set of tech industry partners. Anthropic has said the initial, limited release stemmed from
[7]
Why Anthropic suddenly pulled Fable 5 and Mythos 5 for everyone
Follow ZDNET: Add us as a preferred source on Google. ZDNET's key takeaways * Anthropic pulled Fable 5 and Mythos 5 worldwide. * The US cited national security but gave few details. * Anthropic said the jailbreak claim is narrow and disputed. As of 5:12 p.m. ET on Friday evening, Fable 5 and
[8]
Anthropic backpedals on Fable safety measure
Anthropic has apologized for stealthily throttling its new AI model, Claude Fable 5, with hidden guardrails that undermine both researchers and rivals using it to develop competing systems. The company says it is reversing course and will be more transparent about when the restrictions kick in,
[9]
How Fable 5 And Mythos 5 Change AI Security, Data Retention, And Vendor Risk
Anthropic's Fable 5 and Mythos 5 is the most 2026 product launch you'll read this year. The same model can find nation-state zero days, design novel drug candidates, and play FireRed on a Gameboy Advance with nothing but screenshots. And for the gaming fans out there: yes, we got Fable 5 before
[10]
Anthropic releases Claude Fable, a version of Mythos, days after warning AI is becoming too dangerous
Anthropic is bringing its most powerful AI model to the general public for the first time, but it's doing it with guardrails. On Tuesday, the AI firm launched Claude Fable 5, the first publicly available version of its Mythos model. Anthropic says Fable 5 excels at software engineering, knowledge
[11]
Claude Fable 5 brings Mythos to the masses -- Anthropic's next frontier model is 'state-of-the-art on nearly all tested benchmarks'
Queries regarding cybersecurity, biology and chemistry, and distillation will be redirected to the prior-gen Opus 4.8, however Ever since Anthropic first made the earth-shaking disclosure of its incredibly capable Claude Mythos AI model back in April and the steps it was taking toward a safe
[12]
It blocked us at 'hello!' Anthropic Fable 5 refusing innocuous prompts
Anthropic's newly released Claude Fable 5 generative AI model is trying so hard to be safe that it's hurting its own userbase. Customers attempting to use the AI knowledge regurgitator are reporting that the model is refusing to answer harmless questions, an issue that has annoyed security
[13]
Anthropic rolls out Claude Fable 5, but it's available for a limited time
Anthropic has begun rolling out a new model called "Fable," which is based on the same underlying model as Mythos, its most powerful AI model class. Anthropic previously said that it developed a model called "Mythos," which is a state-of-the-art model that poses security risks to companies around
[14]
Anthropic Releases Claude Fable 5, Its Most Powerful AI Yet, With Cyber Safeguards
On June 9, Anthropic released Claude Fable 5, the most capable model it has ever made, generally available. It also did something unusual: it shipped one model as two products, split not by capability but by a layer of safety classifiers. Fable 5 goes to the public. Its twin, Claude Mythos 5, the
[15]
Anthropic just publically released its Mythos-grade AI at no extra cost for a limited time
* Claude Fable 5 brings Mythos-grade intelligence to general users. * Safeguards reroute some risky queries to Claude Opus 4.8, triggering in * Free on Pro/Max/Team/Enterprise plans until June 23; after that it requires usage credits. It's very easy to get lost in the world of AI developments.
[16]
Anthropic's new Claude Fable 5 is a nerfed Mythos with guardrails attached
Follow ZDNET: Add us as a preferred source on Google. ZDNET's key takeaways * Anthropic is releasing Claude Fable 5 for general users. * Fable 5 uses Mythos-class power with safety controls. * Pricing is about twice that of Claude Opus 4.8. Anthropic has announced a defanged version of its
[17]
Microsoft restricts Claude Fable for employees over data retention concerns
Anthropic released Claude Fable, its first Mythos-class AI model, yesterday and it's already causing concerns inside Microsoft. Sources tell me that Microsoft is limiting the use of Claude Fable 5 for employees because of Anthropic's new data retention requirements. While Microsoft quickly rolled
[18]
Anthropic backtracks on policy that 'sabotaged' researchers' work - Engadget
It wasn't a good look for a company that prides itself on working closely with the academic community. Anthropic is walking back a policy that discreetly hamstrung researchers using its new Claude Fable 5 LLM to create competing AI models, the company told Wired. "We're changing Fable 5's
[19]
Anthropic releases Mythos-like AI model to the public two months after private rollout rocked Wall Street
Two months after Anthropic rolled out Mythos to a limited number of users, citing concerns about the artificial intelligence model's potential to do damage in the wrong hands, the company said it's ready to release an equally powerful model to the public. Anthropic on Tuesday announced Claude
[20]
Anthropic launches powerful Fable 5 model publicly, while keeping Mythos restricted over cybersecurity concerns
Serving tech enthusiasts for over 25 years. TechSpot means tech analysis and advice you can trust. In context: Anthropic's latest release is really a story about control, not just capability. The company is offering two versions of the same underlying model: Claude Mythos 5 for a small circle of
[21]
Anthropic Releases 'Safe' Version of Its Mythos A.I. Technology
Called Claude Fable 5, it is twice as expensive as the company's previous flagship system. In April, Anthropic unveiled a new artificial intelligence system called Claude Mythos. But the company said it couldn't share its new A.I. with the public because Mythos could become a powerful tool for
[22]
Claude Mythos: Anthropic releases version of AI tool despite risk concerns
A version of an artificial intelligence (AI) tool which the company said was too powerful to be released to the public has just been released to the public. Claude Fable 5 is a version of Anthropic's Claude Mythos, an AI program which caused a stir among technology, finance, and government leaders
[23]
Anthropic spins a Fable of a neutered, safer Mythos
It's here. Anthropic's Mythos model, supposedly too dangerous for public release in April, is now available to wreak havoc or tackle other tasks for a hefty price and with some new guardrails in place. Just make sure you don't mind having Anthropic keep some of your data for a while. The AI biz on
[24]
Fable 5 vs GPT 5.5: Anthropic's model dominated every benchmark, then the government pulled it
Anthropic's Fable 5 spent three days as the most capable AI model ever released to the public. It topped the Chatbot Arena leaderboard, crushed OpenAI's GPT 5.5 on coding benchmarks by double-digit margins, and gave paying subscribers access to Mythos-class reasoning for the first time. Then, on
[25]
Anthropic Apologizes For One of the Guardrails on Its Fable 5 Model, and Will Change It
Anthropic's Fable 5 model is the nerfed version of Mythos, which is in turn the model so scarily powerful that it could ostensibly endanger the world if it were released without guardrails. Most of the guardrails, especially the ones designed to prevent users from using Fable to build cyber- or
[26]
Anthropic's too-scary-to-release AI hacking tool is actually coming out -- kind of
Both models show advanced capabilities for tackling even highly complex analytical tasks. By now, you've almost certainly seen at least one AI demo that left you feeling a little off-kilter -- "That's not just good; that's scarily good." Whether we're talking about AI stealing jobs from artists,
[27]
Anthropic finally releases Mythos to the public, but it's so heavily guarded it barely works
Anthropic has been touting the power of its Claude Mythos AI model to find and help fix security vulnerabilities, and it has finally released a public version, Fable 5. However, some cybersecurity experts are complaining that the guardrails meant to prevent abuse are stifling its real-world
[28]
Claude Fable 5 brings Mythos-class capabilities to public users
Anthropic has opened the doors to its most advanced AI system yet, but not without placing guardrails around its most sensitive capabilities. The company on Tuesday unveiled Claude Fable 5, the first publicly accessible version of its Mythos-class AI model. Anthropic says the model outperforms
[29]
Anthropic releases its first Mythos-class model Claude Fable
Anthropic just announced Claude Fable 5, a new AI model it said is the most powerful model it has ever made widely available. According to the company, Fable 5 "shows exceptional performance in software engineering, knowledge work, and vision," with its lead over other models growing as tasks
[30]
Anthropic's Fable AI brings the capabilities of its unreleased Mythos model to regular users - Engadget
Claude subscribers can try the model until June 22 without spending usage credits. Anthropic has just announced Fable, the start of a new family of models that brings many of the capabilities of its Mythos system to the public. As a refresher, Mythos is the state-of-the-art model Anthropic debuted
[31]
The Claude Fable ban highlights a practical AI lesson
Diversifying AI subscriptions across ChatGPT, Claude, and Gemini provides backup options when specific models become unavailable or restricted. What's the real story behind the sudden ban Friday of Claude Fable and Mythos, Anthropic's most powerful AI models? Frankly, I'm as much in the dark as
[32]
Anthropic just released public Mythos-class AI model called Claude Fable, details here
Back in April, Anthropic unveiled its Claude Mythos AI model that it said was too powerful to publicly release. Instead, the company has shared access with software vendors, including Apple, in an effort to use the model for enhanced cybersecurity. Now, as promised, Anthropic has released what it
[33]
Claude Mythos goes public in new Fable 5 model that's 'safe for general use'
As AI models get more powerful, there's also going to be a level of danger. Anthropic announced Mythos not long ago as a model that was too dangerous for public availability, but a new version of that, Claude Fable 5, is now available and, apparently, "safe for general use." In a post today,
[34]
Claude Fable 5 is here -- and it's based on a model Anthropic once deemed too risky for the public
This version comes with guardrails that block some of its most powerful capabilities Back in April, Anthropic surprised the AI world when it revealed Claude Mythos, a model so capable at cybersecurity tasks that the company decided not to release it publicly. Instead, Anthropic limited access to
[35]
Claude Fable 5 curbs: aimed at China, hit AI researchers
The restrictions built to keep China's AI labs out of Anthropic's most powerful model held firm. The way it first enforced them lasted barely two days. Anthropic built the Claude Fable 5 curbs to keep China's AI labs out of its most powerful public model. The loudest complaints came from its own
[36]
Anthropic's Mythos Safeguards Stoke Fears of a 'Permanent Underclass'
On Tuesday, Anthropic launched a new "Mythos-class" model, Fable 5, describing it as being more powerful than any other model the company had ever made generally available. It's a significantly tamer version of Mythos, the behemoth model which Anthropic announced in April but has thus far withheld
[37]
Claude Fable 5 vs GPT 5.5: Is this why the Trump admin banned one and not the other?
Why did the Trump admin ban Claude Fable 5 but not GPT 5.5? This comparison of the two AI models may show why. Credit: Nicolas TUCAT / AFP via Getty Images Earlier this week, Anthropic released its most powerful public model yet: Claude Fable 5. This model is the "safe" version of an even more
[38]
Anthropic releases 'safe' version of Claude Mythos AI model to public
AI company restricted access to Fable 5, its most powerful Mythos model, for months over cybersecurity concerns Anthropic, the maker of the Claude artificial intelligence (AI) models, made a new version of its technology available to the general public on Tuesday while restricting its use in
[39]
Anthropic spent months saying Mythos was too dangerous to release -- then it launched a public version called Fable 5 that it warns 'comes with risks'
Anthropic says Fable 5 brings Mythos-class AI to ordinary Claude users -- but only after the addition of extensive safety controls. For the last couple of months, Anthropic's most powerful AI model existed largely as a warning about the dangers of AI. The company refused to release it publicly,
[40]
Anthropic brings Mythos to the masses with Claude Fable 5, its most powerful generally available model ever
Anthropic today launched two new AI models -- Claude Fable 5 and Claude Mythos 5 -- marking the company's first broad release of the powerful "Mythos-class" AI capabilities it previously kept behind a restricted cybersecurity program. The company says Fable 5, which is the version most users and
[41]
After backlash, Anthropic says its AI will now tell users when their request is being rejected or rerouted for national security concerns | Fortune
Anthropic is changing course after facing criticism for quietly downgrading certain requests to its most capable AI model. On Tuesday, the $965 billion company released a version of its most capable model, Mythos. Anthropic revealed Mythos in April, but held back any Mythos-class models from the
[42]
Anthropic Was So Concerned About Its New Mythos-Based Model's Power That It Lobotomized Its Ability to Improve Itself
Can't-miss innovations from the bleeding edge of science and tech Earlier this year, Anthropic refused to release its Mythos AI model to the public, saying it was simply too dangerous. At the time, executives claimed the model was capable of punching through powerful cybersecurity safeguards,
[43]
Claude's 'too dangerous' AI model is finally public. But there's a catch
The release includes conservative safeguards due to extreme cybersecurity capabilities that could potentially be misused, with a less-restricted version available only to select cyberdefenders. Yes, it's finally happened. A "Mythos-class" Claude model has arrived for the general public. But it's
[44]
The Internet Is Furious at Anthropic After Claude Fable 5 Release
Anthropic's system card confirmed the model silently degrades its own performance on research tasks without notifying the user. Anthropic dropped its most powerful public model on Tuesday, and by Wednesday, a significant chunk of the AI community wished it hadn't. The consensus around Claude
[45]
Anthropic rankles users with safety-first Fable release
Anthropic CEO Dario Amodei, right, and Chief Product Officer Mike Krieger in 2025 in San Francisco.Don Feria / AP Content Services for Anthropic file Anthropic's latest AI model might be the company's most powerful public release, but the system's strict safety measures quickly triggered some of
[46]
Anthropic releases Claude Fable 5, its first Mythos-class model for the public
Anthropic launched Claude Fable 5, its first publicly available Mythos-class model, with safeguards that block high-risk queries and fall back to Opus 4.8. Anthropic on Tuesday released Claude Fable 5, a model built on the same architecture as its restricted Mythos system, making Mythos-class
[47]
Anthropic Releases a Safer Version of Its 'Too Dangerous' Mythos AI
Back in April, Anthropic announced it had built a new AI model, called Mythos, that had an unprecedented ability to find gaps in cybersecurity systems. Citing the risk of the powerful new model falling into the wrong hands, the company initially withheld its public release, only slowly granting
[48]
Using Claude Fable 5 means opting into data collection
Anthropic is changing its data retention policies for its new Mythos-class models. Credit: Nicolas TUCAT / AFP via Getty Images Anthropic just released its most powerful public model yet -- Claude Fable 5. However, along with the model's release, the AI giant also made a significant update to its
[49]
Anthropic to reassess Claude Fable 5 AI development restrictions after backlash
Anthropic's AI restrictions caused concern among founders, researchers and developers following the release of the 'Mythos-like' model. It was just this week that Anthropic launched Claude Fable 5, an AI model that the company claimed has the potential to rival Mythos, albeit with significant
[50]
Anthropic sets AI performance records with new Mythos 5, Fable 5 frontier models
Anthropic sets AI performance records with new Mythos 5, Fable 5 frontier models Anthropic PBC today introduced Claude Mythos 5 and Claude Fable 5, two large language models that it says outperform the competition across a wide range of benchmarks. The LLMs are derived from the Claude Mythos
[51]
Anthropic releases a version of its vaunted Mythos model to developers
The AI startup said Claude Fable 5 is more capable than any other model it has released to the public, showing outstanding performance in software engineering, knowledge work, and vision tasks, among other areas. The model is superior to earlier iterations in performing longer, more complex tasks.
[52]
Anthropic accused of 'secret sabotage' as Claude Fable 5 silently limits capabilities for AI researchers and developers | Fortune
When Anthropic made its first Mythos-tier model available to the general public yesterday, called Claude Fable 5, Fortune reported it was a "considerable step" for the lab, coming just over a week after the company confidentially filed for IPO paperwork. It had initially deemed Mythos-class models
[53]
Anthropic Rolls Out Claude Mythos 5 AI Model -- Along With the Safer Fable 5 for the Public
Mythos drew scrutiny after tests showed it could autonomously discover vulnerabilities and complete complex cyberattack simulations. Anthropic on Tuesday announced the official launch of Claude Mythos 5, a restricted-access AI model the company says has unprecedented cybersecurity capabilities,
[54]
Anthropic launches Claude Fable 5 ahead of $965 billion IPO
Anthropic has launched Claude Fable 5, its first publicly available model in the Mythos class, which features a safeguard system that automatically switches to a safer model in three high-risk areas. The Mythos class represents Anthropic's highest model tier, sharing a base model with the recently
[55]
Anthropic releases state-of-the-art AI model Claude Fable 5, and it's safe to use
Anthropic has officially launched Claude Fable 5, a Mythos-class AI model that now available to the public, and to celebrate the launch Anthropic has also reset current and weekly session limits. The release marks a major milestone for the company, offering users unprecedented access to a powerful
[56]
Crypto Users Wary as Anthropic's Claude Mythos Goes Live
Venture capitalist Simon Dedic said Anthropic's latest AI models drop the cost and skill needed to find crypto exploits to "basically zero." AI company Anthropic on Tuesday released the first public version of its powerful Claude Mythos model, called Fable 5, with some crypto users worried it
[57]
Anthropic releases Fable 5 model, built on the same tech that spooked the government
The Anthropic logo as seen at an event organized by the AI company. Andrej Sokolow / picture alliance via Getty Images file Anthropic released its latest model Tuesday afternoon, heralding the public's first access to the AI company's most powerful class of AI systems. The company says the model,
[58]
The US Government Pulled Fable 5 and Mythos 5, and Maybe the AI Hype Was Justified After All
Every new AI model comes with the same language. Most capable. Most advanced. You've heard it enough times that it starts to blur together. So when Anthropic launched Claude Fable 5 and Mythos 5 on June 9 and said something similar, it was easy to file it away as the usual launch-day framing. Then
[59]
Claude Fable 5: Anthropic releases a 'safe' version of Claude Mythos
Anthropic has released Claude Fable 5, a publicly available version of its powerful but previously restricted Mythos model -- complete with a new set of safety guardrails designed to keep its most dangerous capabilities out of the wrong hands. Along with this "safe for general use" model, Anthropic
[60]
Anthropic Just Released a Powerful Mythos-Class Model to the Public -- With Some Key Safeguards
Anthropic has finally released a version of Claude Mythos, its most powerful model yet, but most people will experience it under a different name. The company just announced Claude Fable 5, its first commercially available Mythos-class model. The Dario Amodei-led company says that the new model's
[61]
Claude just released a Mythos-level model, but you only have 10 days to try it
Outside of the office, Josh can be found digging into the latest video games, fantasy books, or tinkering with the newest features in Windows. * Anthropic has released Fable 5 -- a Mythos-level Claude model available for a limited time. * Tuned for cybersecurity and biology and features robust
[62]
Anthropic rolls out 'Mythos-like' AI model Claude Fable 5
The model reportedly has safeguards built within it to prevent misuse by those who might exploit the technology. Just two months after rolling out Mythos to a limited pool of high-level users, Anthropic has announced the release of Claude Fable 5, an AI model similar to Mythos, but with
[63]
Anthropic releases its first Mythos-class model to the public | Fortune
Now, Anthropic says it is confident new guardrails are enough to ensure these dangerous skills don't fall into the wrong hands. "The reason why we're releasing Fable Five now is very much due to us feeling more confident with our safety guardrails in place," Dianne Penn, Anthropic's head of
[64]
Fable 5: AI Heroics Battle with High Costs, Token Needs
Anthropic's latest AI model Fable 5 has the potential to transform IT operations with its superior coding abilities, but concerns over high compute costs and token consumption may limit widespread adoption, experts said. "Fable's biggest differentiator is its agentic coding capability, which means
[65]
Claude Fable 5 Is Here, But You Probably Won't Need It
If you've been using AI for a while, you probably already know about Claude. A lot of people do. But when most folks talk about AI, they say ChatGPT, the same way people say "Google it" when they mean search. Anthropic has never quite broken into that default. Claude Fable 5 might be its best shot
[66]
Stricter AI Oversight is Coming After the Sudden Claude Fable 5 Shutdown
The sudden shutdown of Anthropic's Claude Fable 5 AI model has sparked widespread discussion about the intersection of technology, security and regulation. The U.S. government ordered the immediate halt of the system, citing security vulnerabilities that allowed users to bypass safeguards and
[67]
Anthropic's latest AIs are making some customers uneasy
Catching a glimpse of Dario Amodei these days is like finding a rare butterfly. The chief executive officer of Anthropic PBC was scheduled to meet with 50 fellow bosses from some of Europe's largest companies in Oxfordshire recently, an exclusive convocation by his firm at a Jacobean-style mansion
[68]
Anthropic Rolls Out Fable 5, Mythos 5 -- One Comes With Limits
Anthropic launched Claude Fable 5, its most capable consumer-facing AI model to date, but with a catch: some sensitive cybersecurity requests are automatically downgraded to a less powerful model. The company said Fable 5 excels at coding, research and other knowledge-intensive tasks, particularly
[69]
Claude Fable 5 & Mythos 5: Key highlights from Anthropic's latest launch
Anthropic has launched Claude Fable 5, its most capable publicly available AI model, excelling in complex tasks and benchmarks. Alongside it, Mythos 5, a restricted version with fewer safeguards, is available for trusted cybersecurity and life sciences users, aiming to accelerate research and
[70]
Microsoft Restricts Employee Access to Anthropic's Claude Fable 5 Over Data Retention Concerns
According to reports, the decision stems from differences in how Claude Fable 5 handles user data compared to other Claude models currently available within Microsoft's ecosystem. A new artificial intelligence model from Anthropic has found itself at the center of an unusual policy divide inside
[71]
Microsoft Balks at Anthropic's Claude Fable 5 Data Retention Policy | PYMNTS.com
Anthropic's data retention policy for the newly released Claude Fable 5, which is a Mythos-class model, includes retaining prompts and outputs for 30 days on every platform on which the model is offered, and for up to two years if the prompts and outputs are flagged by Anthropic's trust and safety
[72]
The Hidden Trade-Offs in Anthropic's New Mythos 5 and Claude Fable 5 Release
Anthropic has officially launched two advanced AI models, Mythos 5 and Claude Fable 5, each catering to distinct user needs with a focus on safety and performance. Mythos 5, part of the exclusive "Project Glass Wing" initiative, is designed for high-stakes applications where precision is paramount,
[73]
When Will Anthropic Release Mythos? - Apple (NASDAQ:AAPL), Amazon.com (NASDAQ:AMZN)
When Will Anthropic Release Mythos? Here's What Prediction Market Is Saying Anthropic is reportedly gearing up to make its advanced Claude Mythos AI model available to a larger audience. According to a Reuters report, Anthropic plans to soon offer Claude Mythos to all customers. This move follows
[74]
Anthropic rolls out Claude Fable 5 and Claude Mythos 5 with improved vision, memory, and research abilities
Anthropic has introduced Claude Fable 5, a Mythos-class model designed for general use with safety safeguards, and Claude Mythos 5, a restricted-access version for cybersecurity defenders and scientific research partners. Both models share the same underlying system, with Mythos 5 operating under
[75]
Claude Fable 5: The Powerful AI Model That Anthropic Released with Guardrails in Place
Anthropic is releasing the version a day after arch rival OpenAI decided to file papers for an IPO, in what has become a race to supremacy between the two companies Anthropic today revealed that it has released its most powerful AI model to the general public and it comes with adequate guardrails.
[76]
Anthropic Launches Mythos-Class Models After Developing Safeguards | PYMNTS.com
Claude Fable 5 is safe for general use, while Claude Mythos 5 will initially be released for only a small group of cyber defenders and infrastructure providers through Project Glasswing, according to the release. The launch of these models follows the limited release in April of the first
[77]
Anthropic's Fable 5 draws mixed reactions from early users
Anthropic's new AI model, Claude Fable 5, is here. Early users see big improvements in handling complex tasks like software development and design. Experts praise its advanced capabilities. However, concerns are rising about its cost and how easily people can access it. The model is currently in
[78]
Anthropic opens Mythos-class AI to the public with data retention
* Read Anthropic's Mythos announcement here. Anthropic has launched two Mythos-class models on June 9, 2026: Claude Fable 5, the first such model it has made publicly available, and Claude Mythos 5, restricted to vetted cybersecurity partners. The two run on the same underlying model, and
[79]
Why Anthropic's Fable 5 Marks the End of Free AI Services
Anthropic's latest release, Fable 5, represents a significant step forward in artificial intelligence, combining advanced reasoning capabilities with a strong focus on safety and ethical use. As detailed by Prompt Engineering, one standout feature is its ability to autonomously manage complex
[80]
Anthropic Launches Claude Fable 5 with Advanced Safety Controls
Anthropic has unveiled Claude Fable 5, its most advanced public AI model yet. The launch combines stronger reasoning and coding capabilities with new safety measures designed to limit misuse in high-risk domains. Anthropic has introduced Claude Fable 5, the first publicly available model from its
[81]
Anthropic rolls out public version of Mythos without cybersecurity capability
Anthropic is rolling out a public version of its Mythos AI model, but with guardrails barring its use in risky areas such as cybersecurity, after a preview earlier this year sent shockwaves globally with its ability to find software flaws. The new Claude Fable 5 is the most powerful model
[82]
Anthropic, which claimed AI model was too risky for public to use, releases 'safe' version
After hyping potential safety threats posed by its latest AI model, Anthropic says it is releasing a version with tweaks that make it "safe" for the general public. A day after filing for its initial public offering, the company on Tuesday trumpeted a new version of the Mythos model with
[83]
Anthropic unveils Claude Fable 5, making a shift toward autonomous AI agents
Anthropic has launched Claude Fable 5 and Claude Mythos 5, introducing a new class of AI models designed for long-horizon, autonomous tasks. The release highlights the industry's shift toward agentic AI, combining breakthroughs in software engineering and scientific research with stringent
[84]
Claude Mythos 5 and Fable 5 Officially Launch
Anthropic's latest AI models, Claude Fable 5 and Claude Mythos 5, mark a significant step forward in artificial intelligence development. As highlighted by Nate Herk, these models belong to the new Mythos class, which introduces distinct capabilities tailored to different user needs. Claude Fable
[85]
Anthropic opens most powerful AI model to public with safeguards
Anthropic, maker of the Claude artificial intelligence (AI) models, on Tuesday made the most powerful version of its technology available to the general public while restricting it from use in sensitive areas. most queries to it relating to sensitive issues like cybersecurity will be routed instead
[86]
Microsoft is restricting Claude Fable 5 for staff despite its AI ambitions, here is why
Microsoft has not added Claude Fable 5 to the internal version of GitHub Copilot that employees use for work. Anthropic recently launched Claude Fable 5, the first Mythos-class AI model designed for public use. The company claims that Fable 5 offers similar capabilities as Mythos AI while adding
[87]
Claude Fable 5 is the beginning of the end of 'one model for every use case': Here's how
I remember when the big AI story was whether these models could pass a bar exam. Now one of them is designing drug candidates without a human in the room. We moved fast. Yet there is an underlying change in Anthropic's release of Fable 5 and Mythos 5 that strikes me as more significant than any
[88]
Claude Fable 5 is less risky Mythos model: Safest AI right now?
Over 1,000 red-team hours found no universal jailbreaks before launch, claims Anthropic Anthropic's much-anticipated Mythos class model finally dropped, called as Claude Fable 5. Before getting into what makes this latest AI model from Anthropic so unique, it's also an industry-first of sorts in
[89]
Using Claude Fable 5? Anthropic says some topics are too dangerous to discuss, here is why
Anthropic is keeping its most powerful AI tools available only to trusted users while it assesses potential risks. Anthropic has launched Claude Fable 5, a more secure version of its Claude Mythos 5 AI model, alongside a new set of safeguards aimed at limiting misuse. The company says the latest
[90]
Anthropic launches Claude Fable 5, a safer Mythos AI model: Features, availability and how to use it
The company says Fable 5 offers similar capabilities as Mythos AI while adding safety measures. Anthropic has launched Claude Fable 5, the first Mythos-class AI model designed for general use. The company says Fable 5 offers similar capabilities as Mythos AI while adding safety measures to reduce
[91]
Anthropic may release Claude Mythos for public this week: Here is why it is a big deal
Anthropic has not confirmed the launch, but the release could bring some of its latest AI features to more users. Anthropic is reportedly gearing up to publicly launch Claude Mythos. The news comes right after Apple's WWDC26 event and OpenAI filing for its IPO. With the public version of Mythos,
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Anthropic unveiled Claude Fable 5, its first publicly available Mythos-class AI model, with unprecedented safety restrictions on cybersecurity, biology, and chemistry topics. The model automatically routes sensitive queries to an older version, Claude Opus 4.8. While Anthropic says the guardrails prevent malicious use, cybersecurity researchers complain the restrictions are overly broad, blocking even routine code reviews and security work.
Anthropic Launches Claude Fable 5 With Unprecedented AI Model Safeguards
Anthropic publicly released Claude Fable 5 on Tuesday, marking the first time its Mythos-class AI model has become accessible beyond a select group of trusted partners. The publicly available AI model represents a significant advancement over previous Claude Opus models, but it arrives with stringent AI safety measures designed to prevent misuse in high-risk AI topics including cybersecurity, biology, and chemistry
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. When users attempt queries on these sensitive subjects, Claude Fable 5 automatically reroutes them to the earlier Claude Opus 4.8 model and displays a warning notification1
.The launch comes alongside Claude Mythos 5, which operates on the same underlying technology but remains restricted to organizations approved through Project Glasswing, Anthropic's program for vetting cybersecurity professionals
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. Anthropic acknowledged it has tuned these guardrails to be "stricter than ideal," accepting that the system may occasionally refuse harmless requests. The company reports false positives occur in less than five percent of all sessions during testing, a tradeoff it considers necessary for preventing AI misuse1
.Cybersecurity Restrictions Draw Sharp Criticism From Researchers
The implementation of cybersecurity restrictions has triggered significant pushback from security professionals who argue the limitations are too broad and hinder legitimate work. Valentina "Chompie" Palmiotti, a security researcher at IBM X-Force, noted that Claude Fable 5 "rejects any request that could be tangentially cyber related. Even innocuous tasks like reading a blog post"
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. Matt Suiche, a member of the technical staff at AI cybersecurity startup Tolmo, explained that "if you ask it to write secure code, it assumes it is cybersecurity related work instead of software engineering best practices, and you get downgraded"2
.Anthropic's concerns center on the model's capability for agentic hacking, which allows it to execute multi-part cyberattacks with far greater facility than earlier models
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. Testing from the UK's AI Security Institute found that Mythos Preview performed similarly to OpenAI's GPT-5.5 on Capture the Flag challenges, suggesting the performance isn't unique to one model1
. On the cybersecurity-focused ExploitBench test, Claude Mythos 5 scored 78 percent on vulnerable code exploits, jumping from Opus 4.8's 40 percent and even surpassing Mythos Preview's 69 percent1
.Anthropic Reverses Policy on Secret AI Research Sabotage
Anthropic faced fierce backlash from the AI research community after initially planning to secretly degrade Claude Fable 5's performance for users attempting frontier AI development work. The company would have invisibly limited the model's capabilities for researchers trying to build competing AI models, which Anthropic explicitly bans in its terms of service
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. Dean Ball, a senior fellow at the Foundation for American Innovation and former White House AI advisor, called the "secret sabotage" policy "shockingly hostile" and noted it undermines collaboration on AI safety3
."We're changing Fable 5's safeguards for frontier LLM development to make them visible," Anthropic said in a statement. "We made the wrong tradeoff and we apologize for not getting the balance right"
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. Will Brown, research lead at open source AI startup Prime Intellect, expressed concern that the policy suggested Anthropic was "starting to pull the ladder up behind them" by limiting who could conduct advanced AI research3
.Biological Weapons Concerns Expand Safety Protocols
While earlier Anthropic models blocked bioweapons-related queries, the classifier now applies to all chemistry and biology-related questions in Claude Fable 5. The company worries that "well-resourced malicious actors" could use even seemingly benign queries on these subjects to assist with "highly risky biological research" more effectively than with previous models
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. Anthropic has described AI-enabled bioterror risks as a horrifying reality that has concerned leading AI labs in recent months5
.Anthropic is expanding its trusted access program for life sciences organizations, which will remove biology and chemistry safeguards while maintaining cybersecurity restrictions. This expansion happens "in consultation with the US government" as the company determines who qualifies as trustworthy enough to access potentially dangerous capabilities
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. The Cyber Verification Program requires cybersecurity professionals to apply for approval to receive fewer limitations when using Claude for security work, similar to OpenAI's Trusted Access for Cyber program2
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Pricing and Access Raise Concerns About AI Costs
API and Enterprise users can access Claude Fable 5 at $10-per-million input tokens and $50-per-million output tokens, prices that are 67 to 100 percent higher than OpenAI's GPT-5.5
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. This price difference could prove significant as many enterprises grow critical of AI costs after blowing through yearly AI budgets early4
.Anthropic's existing subscription plans include access to Claude Fable 5 through June 22, after which users will need to purchase usage credits to access the model
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. The company says it eventually hopes to restore access as a standard part of subscription plans once it has "sufficient capacity"1
. With the launch, Anthropic will require a 30-day retention on all traffic, even for enterprises that previously had zero-retention agreements, to defend against complex attacks and identify false positives4
. This mandatory data retention policy could set an industry precedent where access to increasingly powerful models comes with surveillance measures framed as preventing AI misuse4
.Implications for AI Development and Recursive Self-Improvement
The launch follows Anthropic's recent warning that AI systems are advancing so rapidly they may soon achieve recursive self-improvement, where models autonomously improve themselves without human intervention
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. In over 1,000 hours of red-team testing with a bug bounty program, external teams failed to find universal jailbreaks for Claude Fable 5, and the model resisted automated jailbreak attempts to a much larger degree than previous Claude Opus models1
.Third-party testing shows impressive capabilities: analytics company Hex reported Claude Fable 5 was the first to score 90 percent on its core analytics benchmark of complex, long-running analytical tasks
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. The model also reportedly beat Pokemon FireRed, something previous models had failed to accomplish5
. As Anthropic prepares to enter public markets alongside OpenAI and Elon Musk's SpaceX, the company's approach to AI safety measures will face continued scrutiny from both the AI research community and regulators watching how frontier labs balance innovation with responsible deployment4
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