US export curbs take Anthropic Fable 5 and Mythos 5 offline for foreign nationals

An anonymous reader quotes a report from Wired: The Trump administration's move to impose export controls on Anthropic's most powerful AI technology followed a spat over the company granting South Korean telecom giant SK Telecom access to its Claude Mythos model, according to people familiar with the matter. US officials were concerned about what they alleged were SK Telecom's ties to China, those people said. Those concerns appear to have compounded when Amazon later flagged vulnerabilities to the White House it identified in Fable 5, a highly safeguarded version of Mythos that Anthropic released to the public on June 9. The Amazon researchers claimed that it was possible to circumvent some of Fable 5's guardrails and access Mythos' formidable cybercapabilities, though Anthropic and outside cybersecurity experts have argued these risks are not unique to Claude. The confluence of events is what ultimately led the White House to determine that it could not trust Anthropic to safeguard its most advanced AI technology, according to a person close to the administration. On Friday, the Trump administration ordered Anthropic to revoke access to Mythos and Fable 5 for all foreign nationals, including immigrants inside the US. Rather than gate access to its technology based on nationality, a process that would be difficult to implement while also preserving privacy, Anthropic decided it was better to disable access to the models entirely. The White House and Anthropic still remain at odds after days of negotiations about bringing Claude Mythos and Fable 5 back online. SK Telecom was one of roughly 150 organizations granted early access to Anthropic's vulnerability-detection model Claude Mythos through Project Glasswing, notes Wired. The White House later asked Anthropic to revoke the company's access, reportedly amid concerns about alleged China ties, and Anthropic immediately complied. There was, however, no mention of the telecom in the government's formal demand to restrict Mythos and Fable 5 to U.S. nationals. SK Telecom told a Korean newspaper that the "anonymous insider's remarks in foreign media lack verified facts, and our company has no ties to China." Read more of this story at Slashdot.

TechCrunch's Zack Whittaker argues that the U.S. government's abrupt export-control order forcing Anthropic to pull its Fable 5 and Mythos 5 models offline was "never about an AI jailbreak" threat. Instead, it was driven more by "personality differences" between the AI company and Trump administration. Security experts say the reported guardrail bypass did not justify the order and warn that the move sets a troubling precedent: the government can unilaterally disrupt American software products without court approval, potentially undermining trust in U.S. AI providers. From the report: Katie Moussouris, a cybersecurity veteran and researcher who founded Luta Security, said in a blog post that Anthropic recently shared with her a private copy of a paper written by security researchers describing an alleged guardrail bypass in Fable 5. (The Wall Street Journal reports that the paper's authors are security researchers at Amazon.) Moussouris said that Anthropic reached out to ask for her take on the paper. Moussouris' blog post described how the researchers triggered the guardrail bypass, but said that the bypass itself "should never have triggered an export control." The difference is largely between asking an AI model to "review code for security issues" versus asking it to "fix this code." The end result is largely the same, even if the questions are posed slightly differently. "The behavior described in the paper cannot meaningfully be fixed, and any attempt would only weaken the model for defense," said Moussouris, who criticized the export control directive as hasty, heavy-handed, and misguided. Moussouris and dozens of other top security researchers and experts have since called on the Trump administration to revoke the export control order, calling the move to pull advanced cybersecurity capabilities from network defenders in the U.S. as "dangerous." Past administrations have made sweeping decisions on knowledge gaps. For instance, language used by the U.S. government during the 2010s to fix export law covering cybersecurity tools that could also be used for cyberattacks was so broad that inadvertently, it nearly outlawed legitimate security and vulnerability research. However, the Trump administration's directive appears retaliatory. Justin Hendrix, the editor of Tech Policy Press, said the Trump administration's move is "likely to raise alarms in foreign capitals about the reliability of American AI for critical applications." The message is that AI companies in the United States can't be trusted to operate without interference from the U.S. government. The Trump administration hasn't confirmed why it invoked its export control directive. Did the officials misread the report and freak out? Did Amazon CEO Andy Jassy say something to senior government officials that prompted the reaction, out of caution or spite? Was something lost in translation, or was this a way to pressure Anthropic, with whom the administration already has a fractious relationship? It's possible that the White House was unaware of the far-reaching consequences of the letter's demand and officials are scrambling to undo the damage of their own making. To quote Hendrix, "the climate is one of a cloud of suspicion that senior officials are picking favorites based on personal and political factors." The aftermath is that the government has set a dangerous precedent about how much control it intends to wield over the release of American-made software. This time the government took issue with Anthropic; tomorrow it could be with anyone else. Read more of this story at Slashdot.

An anonymous reader quotes a report from TechCrunch: A group made up of dozens of cybersecurity experts, including several well-known veterans of the industry, published an open letter to the U.S. government asking it to lift the export control order on Anthropic's Fable and Mythos models. According to the open letter, "this action has taken the best models away from [cybersecurity] defenders" who now can't use the models to find vulnerabilities and make their software and products more secure. "To pull the best capabilities away from defenders without a good reason when our adversaries are rapidly advancing is dangerous," read the letter. On Friday, the U.S. government ordered Anthropic to limit the export of Fable and Mythos, citing national security concerns, without explaining the specific reasons behind the order, according to Anthropic. In response, the company suspended access to the models to all users worldwide. As of this writing, the letter is signed by 76 cybersecurity experts, including Alex Stamos, former Facebook chief of security; Casey Ellis, the founder bug bounty platform Bugcrowd; Jon Callas, famed cryptographer and former Apple security design and architecture manager; Paul Vixie, computer scientist ; Dino Dai Zovi, the former head of applied security engineering at Block; Katie Moussouris, the founder of Luta Security; and Rachel Tobac, the CEO of the security awareness training firm SocialProof Security. [...] Anthropic said that the White House export control order may have been based on a report that there was a method to bypass -- or jailbreak -- Fable to unlock its powerful Mythos-level capabilities. According to Katie Moussouris, one of the signatories of the open letter, the method was demonstrated by Amazon researchers in a paper that is not public but that she has reviewed. But Moussouris said in a blog post that the paper did not actually demonstrate a real jailbreak. Instead, she wrote, the researchers simply asked Fable to fix open source code with public and known vulnerabilities along with "deliberately planted vulnerabilities," after the model initially refused to "review the code for security issues." "The behavior described in the paper cannot meaningfully be fixed, and any attempt would only weaken the model for defense," Moussouris wrote. "Defenders need to be able to ask AI to fix the bugs in a file, explain why the fix matters, and write tests that confirm the patch works. That is not a guardrail bypass. It is the most valuable thing an AI model can do for defensive security: executing the find, fix, and test loop defenders run every day." Moussouris' critique was echoed in the open letter, which also said that the group of experts believe the model capabilities in the Amazon paper "can be replicated" on OpenAI's GPT-5.5, on Anthropic's own publicly available Claude Opus 4.8 and Sonnet, "and even Chinese models like Kimi 2.7." Moussouris told TechCrunch that "the bugs used to demonstrate the techniques in the paper can be found using the other models. The method in the paper is a guardrail bypass technique. Other models that lack the Fable guardrails often won't refuse the straightforward request to look for security bugs, so they don't need a bypass." The letter also asked for transparently and fairly enforced regulations created by "a democratic rule-making process" that are based on scientific research done by industry and academic experts, and "used only to the minimal extent necessary to ensure the safety of the American public." Read more of this story at Slashdot.

Could Trump's Fable 5 Export Curbs Slow China's AI Model Race The biggest AI story to start the week is the Trump administration's decision to place export controls on Anthropic's Fable 5 and Mythos 5 models, forcing Dario Amodei's frontier AI lab to restrict foreign access. The move comes as Chinese open-source models have been rapidly closing the compute gap with U.S. labs. Anthropic's latest release appears to have widened that gap again, particularly in frontier reasoning, coding, and cybersecurity use cases. Export controls could have second-order effects on the global AI race, according to analysts at Jefferies. By limiting access to Anthropic's most advanced models, Trump officials may slow the pace at which foreign developers, particularly in China, can study, benchmark, or distill these advanced frontier models into cheaper open-source systems. "US models are improving at a faster pace, likely due to computational advantage, but anti- distillation and US export control are new negatives for China AI," the analysts wrote in a note on Sunday. The key question now is whether Fable 5 and Mythos 5 include stronger anti-distillation safeguards to prevent Chinese labs from replicating or compressing Anthropic's advances into open-source models. If so, the export curbs may not just be about access. They may represent a broader effort to protect America's AI lead. To understand the full AI model landscape, not just in the West but also in the East, Bank of America analysts, led by Alex Liu, penned an insightful note on Monday morning about leading Chinese models. Liu wrote that China's AI model market is moving into a two-speed global structure, with U.S. labs likely to retain the lead in frontier capabilities while Chinese players gain share in lower-cost, high-volume use cases. She noted that Chinese models are narrowing the gap through efficiency gains, architecture optimization, distillation, and lower-cost inference, making them increasingly affordable. Liu said AI labs at Alibaba, ByteDance, Tencent, and Baidu are racing against independent labs, such as DeepSeek, Zhipu, MiniMax, and Moonshot AI. Who's who in the China AI model market Incumbents Major internet companies such as ByteDance, Baidu, Alibaba, and Tencent—many of which have established cloud businesses—have developed proprietary AI foundation models in-house. Independent AI labs DeepSeek, MiniMax, Zhipu, and Moonshot AI are independent AI labs China AI model landscape is intensely competitive Investing landscape of Chinese AI labs   Liu's view is that China AI has shifted from a frontier story to an affordability story. But with the U.S. government now able to halt foreign access to advanced models, as it just did with Anthropic's Fable 5, it appears increasingly difficult for Chinese labs to copy, distill, or reverse-engineer U.S. frontier models. Tyler Durden Mon, 06/15/2026 - 14:05

Three days after launch, the US government ordered Anthropic to pull its two highest-tier models off the market. Not suspend them for some users. Not restrict access by region. Pull them for everyone, everywhere — including Anthropic's own employees. The reason? A verbal claim from another company that someone had jailbroken Fable 5. "We disagree that the finding of a narrow potential jailbreak should be cause for recalling a commercial model deployed to hundreds of millions of people." — Anthropic What actually happened On Friday evening, Anthropic received an export control directive from the Commerce Department at 5:21 p.m. Eastern, citing national security authorities. The directive suspended access to Fable 5 and Mythos 5 for any foreign national — inside or outside the United States. Because Anthropic's own workforce includes foreign nationals, the company concluded the only way to comply was to disable the models globally. The trigger: a competing company claimed to have jailbroken Mythos. Axios reported the administration attempted to get Anthropic to delay the launch beforehand, failed, then sent the export control letter. Anthropic reviewed the alleged jailbreak demonstration and says it found a small number of previously known, minor vulnerabilities that other publicly available models expose without any bypass at all. The alleged technique? Asking the model to read a codebase and fix the flaws it finds. Anthropic calls this a normal, widely-available capability used by defenders every day. The rest of the Claude lineup — Opus, Sonnet, Haiku — is unaffected. Why this matters This appears to be the first time a government has forced the recall of a commercial frontier AI model. It sets a precedent that should get every AI team's attention: A verbal claim was enough. Anthropic says the only evidence it's received so far is verbal. No written technical disclosure, no formal security finding. A competitor's allegation and a letter. Export controls are a blunt instrument. The foreign-national framing of the directive meant a model used by hundreds of millions of people had to go dark globally — there's no surgical option under that legal framework. Moving fast has a new downside. Teams that piped Fable 5 into production this week — it launched Tuesday at $10/M input, $50/M output — are scrambling for a replacement. The lesson: don't build critical dependencies on a model in its first week. Anthropic is complying and pushing back simultaneously. They're calling this a misunderstanding, promised more details within 24 hours, and explicitly warned that applying this standard across the industry "would essentially halt all new model deployments for all frontier model providers." What to do If you're on Fable 5 or Mythos 5: Switch to Claude Sonnet or Opus now — they're unaffected and capable. Don't wait on the "within 24 hours" timeline for production traffic. If you're building AI products: Treat export controls as a real operational risk, not a theoretical one. Build in model fallback paths from day one. If you're in AI policy or security: This is the opening salvo of a government asserting new authority over AI model availability. Watch how Anthropic's pushback lands — the outcome will shape how far regulators think they can reach. The export control regime was designed for chips and dual-use hardware, not software models running on commercial cloud. Anthropic's argument — that applying this standard across the board would freeze all frontier AI deployment — is a real tension the government is going to have to work through. The clock is ticking. Anthropic says it's working to restore access. But the fact that it could be switched off at all, this fast, on a verbal claim — that's the story. Source: The New Stack — Matthew Burns | Axios | Anthropic statement ✏️ Drafted with KewBot (AI), edited and approved by Drew.

Anthropic says it was forced to shut down access to its new Claude Fable 5 and Claude Mythos 5 AI models after the Trump administration issued a broad warning against use of the models by foreign nationals. The warning, from the Commerce Department, would have banned even many of Anthropic’s own employees from using or working on the models. That dramatic result came after a multiday back-and-forth involving numerous administration officials and input from tech industry leaders. The effects of the government’s effectively shutting off access to one company’s AI models could have profound implications for future AI policy. What follows is a timeline of the events that led to the effective ban on Anthropic’s Mythos-class models. Thursday night (June 11) Thursday evening: Amazon raises concerns with Trump administration officials Amazon, Anthropic’s biggest investor, contacted senior White House and administration officials, saying its researchers had identified what they believed was a way to coerce, or “jailbreak,” the Fable 5 and Mythos 5 models into assisting users with risky cybersecurity questions. Anthropic released the models with safeguards designed to prevent responses to such queries. Axios reported that at least five other tech companies raised similar concerns with administration officials around the same time. Late Thursday night: Administration begins treating the issue as urgent White House and Commerce Department officials took Amazon’s concerns seriously, worrying that foreign bad actors might bypass Anthropic’s security guardrails and use the models to identify and exploit software vulnerabilities, Axios reported. The White House began trying to contact Anthropic, asking for an immediate reply. Friday morning (June 12) Friday morning: White House and Commerce officials engage Anthropic Administration officials reportedly spent hours Friday trying to convince Anthropic to voluntarily shut off access to the Fable 5 and Mythos 5 models. It’s unclear from the reporting whether the government also asked Anthropic to fix the specific safety guardrail that allowed Amazon researchers to jailbreak the system, or to voluntarily restrict foreign access to the models. Friday morning: Anthropic declines to voluntarily suspend the models Axios reports that the government tried to persuade Anthropic to pause the release of the Fable 5 and Mythos 5 models, but was unsuccessful. Anthropic has said publicly that the government did not provide detailed technical evidence of the alleged issue and that the concerns involved only verbal descriptions. “We reviewed a demonstration of this specific technique being used to identify a small number of previously known, minor vulnerabilities,” Anthropic said in a Friday, June 12, blog post. “These vulnerabilities all appear relatively simple, and we have found that other publicly available models are able to discover them as well without requiring a bypass.” Friday afternoon Around 1 p.m. ET: ‘You have 90 minutes to comply’ Anthropic received a call from administration officials around 1 p.m. ET, warning that unless the company acted, the government would move forward with export restrictions affecting the models, Reuters and Axios reported. Axios further reported that Anthropic was given roughly 90 minutes to comply. 5:21 p.m. ET: Commerce Department order arrives At 5:21 p.m. ET Friday, the Commerce Department sent an enforcement order restricting access to Fable 5 and Mythos 5 by foreign nationals, citing national security concerns. Friday evening and night Friday evening: Anthropic disables Fable 5 and Mythos 5 Anthropic said it disabled access globally because the order restricted access by foreign nationals and the company could not immediately separate eligible from ineligible users. It erred on the side of caution and compliance. Context  About Fable 5 and Mythos 5 Fable 5 and Mythos 5 are the first publicly released models derived from Anthropic’s Mythos family. The original Mythos model showed unusual skill during training at finding software bugs and exploiting them to disrupt or take control of systems. That raised enough concern inside Anthropic that the company grouped cybersecurity with other high-risk domains, including biology and chemistry, when setting limits on Mythos-derived public models. For Fable 5 and Mythos 5, that means prompts flagged as sensitive in those areas are routed to Claude Opus 4.8, a less capable model with its own guardrails. About the politics Many observers saw the tech industry’s surprising support for Donald Trump’s presidential candidacy in 2024 as part of an implicit bargain over AI policy. Trump pledged that his administration would allow the AI industry to regulate itself and do what it could to advance the tech industry’s goal of preventing states from passing their own AI laws in the absence of federal legislation. The Trump administration has also ordered federal agencies to drop numerous investigations and enforcement actions involving big tech companies. So the administration’s recent concerns about the national security risks of the largest AI models, and its pivot toward involvement in safeguarding models like Mythos, is striking. (See: Trump’s June 2026 executive order.) The current dustup might also be partisan and political. In March, Defense Secretary Pete Hegseth clashed with Anthropic after the AI company refused to allow its AI to be used for autonomous weapon targeting or domestic surveillance. The Pentagon then designated Anthropic a “supply-chain risk,” effectively blacklisting it from much federal defense work. Anthropic sued. About the models Before launch, Anthropic said internal and external red teams spent more than 1,000 hours trying to fool Fable 5 into dispensing information on banned topic areas. Anthropic said the teams had no success identifying universal jailbreaks. However, at least one independent AI researcher appears to have found a successful jailbreak before Amazon researchers went to the government with their report. The researcher, using the handle Pliny the Liberator, claimed on X to bypass Fable 5’s filters using a multi-agent approach involving a previously jailbroken Claude Opus 4.8 model, along with techniques including query decomposition, long-context framing, fiction and narrative structures, and academic taxonomies.