Anthropic has announced that the US government has lifted export controls on its newest artificial intelligence models, Claude Fable 5 and Claude Mythos 5, paving the way for the high-profile systems to return to active use.

The AI research and development company had temporarily suspended access for all users following the June 12 imposition of the restrictions, which blocked foreign nationals both inside and outside the US from accessing the models. Anthropic stated that the complete suspension was necessary because it was unable to perform real-time nationality verification. With the lifting of the export controls, the access restrictions have now been terminated.

Anthropic announced that Claude Fable 5 will be made available for global general availability starting Wednesday, July 1, across the Claude Platform, Claude.ai, Claude Code, and Claude Cowork. Users on Pro, Max, Team, and select Enterprise plans will be permitted to use Fable 5 for up to 50% of their weekly usage limits at no additional cost until July 7.

After that date, access will be transitioned to a usage-credit basis. The company is also working to restore access via Amazon Web Services (AWS), Google Cloud, and Microsoft Foundry as quickly as possible.

Meanwhile, access to Claude Mythos 5—a model designed for defense-oriented cybersecurity work that operates with fewer safety constraints—was restored to select US entities following approval from the US government on June 26.

The company stated that it continues to work in coordination with the US government to expand access to domestic and international partners under its Glasswing program.

The cybersecurity report that triggered export restrictions

According to the timeline disclosed by the company, the export controls were instituted on June 12, just three days after the models’ June 9 launch. The regulatory intervention was triggered by a report from Amazon researchers who successfully bypassed the safety guardrails of the Fable 5 model to identify specific software vulnerabilities.

The report highlighted a single instance where the model generated code demonstrating how the vulnerability in question could be exploited. Anthropic collaborated with the US government and partners, including Amazon, over a two-week period. During subsequent testing, Anthropic confirmed that lower-capacity models—such as Claude Opus 4.8, GPT-5.5, and Kimi K2.7—were also capable of identifying the same vulnerabilities.

Furthermore, the tests revealed that the code demonstrating how to exploit the vulnerability could be generated by all tested models, including Claude Haiku 4.5, Sonnet 4.6, Opus 4.7, GPT-5.4, and Kimi K2.7.

Anthropic maintained that the bypass technique did not expose any unique offensive cyber capabilities at the Mythos level, describing it instead as a borderline case involving routine defensive activities.

Nevertheless, in cooperation with the US government, the company trained an advanced safety classifier targeting the behavior identified in the report, which it claims blocks the exploit with a success rate of over 99%.

When cybersecurity-related queries directed at Fable 5 are blocked by this system, users will be notified and their prompts will be automatically redirected to the Opus 4.8 model.

Anthropic acknowledged that the new safety mechanism carries the risk of triggering more frequent false positives—blocking harmless queries during routine coding and debugging—but said it is optimizing the system to reduce these occurrences.

The company noted that Claude Mythos 5 is more capable of finding and exploiting cybersecurity vulnerabilities than any actor other than high-level human experts, making it an attractive target for malicious actors.

In contrast, Claude Fable 5 does not possess these offensive cyber capabilities. Anthropic stated that it doubled its staffing resources in the month leading up to the launch to implement its most robust cybersecurity measures to date on the model.

This approach, termed “defense-in-depth,” combines training the model to reject dangerous requests with the deployment of automated cybersecurity classifiers.

These classifiers, which function as smaller auxiliary AI systems, detect and block suspicious requests during cybersecurity operations. To counter the risk of “jailbreaking”—where users manipulate the system to bypass safety rules—Anthropic expanded its safety margins significantly.

While the company acknowledged that this conservative posture leads to the blocking of some harmless queries, it stated that the trade-off was necessary to prevent offensive cyber exploits.

Researchers at the Center for AI Safety and Innovation (CAISI), an agency under the US Department of Commerce, also evaluated the new measures and confirmed that the cybersecurity guardrails are highly robust.

A call for industry-wide safety standards

Pointing to a lack of objective, industry-wide standards to evaluate the severity of safety guardrail bypasses, Anthropic announced that it has begun developing a consensus-based framework alongside Amazon, Microsoft, Google, and other Glasswing partners.

The proposed cybersecurity assessment framework aims to score the severity of vulnerabilities based on four distinct criteria:

• Capability gain: The degree to which a vulnerability empowers a user beyond currently available tools.
• Scope of capability gain: The number of different offensive tasks that can be executed using the same bypass technique.
• Ease of weaponization: The level of human effort required to convert the method into an active exploit.
• Discoverability: How easily the technique can be identified and acquired.

Additionally, the company is launching a new HackerOne bounty program where security researchers can report cybersecurity vulnerabilities they discover within the Fable 5 model.

Deepening cooperation with the US government

Over the past ten weeks, Anthropic has worked closely with cybersecurity and national security agencies under the framework of the June 2 US Executive Order on “Promoting Advanced AI Innovation and Security.” The company announced it will further deepen its public-sector collaboration.

Under this expanded partnership, Anthropic will provide early, pre-launch access to critical national security-relevant models to government partners for independent testing.

The company has pledged to share information rapidly if vulnerabilities or abuse patterns are detected, and to submit newly developed safeguards to state agencies for evaluation.

Furthermore, Anthropic will establish dedicated internal teams focused on joint AI safety research and will allocate significant computing resources to support government-backed testing initiatives.

The company emphasized that transparent, permanent, and robust legal regulations applied equally to all frontier model developers are critical for the future of cyber defense.

A coalition of 25 US states and the District of Columbia has filed a joint lawsuit against the Trump administration, challenging a new regulation that restricts work-requirement exemptions for medically frail individuals under Medicaid, the government health insurance program for low-income populations.

The lawsuit, filed on Monday in the US District Court for the District of Massachusetts, alleges that the Centers for Medicare & Medicaid Services (CMS) violated statutory protections established by Congress through its issuance of an interim final rule governing who qualifies for exemptions from the new work mandates.

In their joint complaint, the states argue that the newly adopted rule “dramatically narrows the work exemption boundaries legally secured by Congress for some of the most vulnerable members of the Medicaid program.”

The states contend that the regulation will cause a significant number of individuals who are currently working or who legitimately qualify for exemptions to lose their health coverage or be denied access to these vital services.

“This regulation introduces new rules that restrict who should be exempted due to their medically frail status, forcing these vulnerable individuals who require healthcare services to navigate unnecessary bureaucratic hurdles to obtain and maintain their vital health coverage,” the lawsuit states.

The rule, published earlier this month, serves as implementation guidance for how the work requirements enacted under the “One Big Beautiful Bill Act” will be applied across 42 states and the District of Columbia.

Republican lawmakers and administration officials have defended the policy, characterizing it as a mechanism to combat waste, fraud, and abuse within the Medicaid program.

Under the new rules, which are scheduled to take effect in January, beneficiaries enrolled in expanded Medicaid programs must work, participate in volunteer activities, attend an educational institution at least part-time, or take part in job training programs for at least 80 hours per month to maintain their insurance coverage.

While the statutory text of the legislation outlines various exceptions for specific vulnerable groups—explicitly exempting “medically frail” individuals from the mandate—the statute did not provide a precise definition for the term.

The administration’s new rules narrow the definition of medical frailty by tying it directly to an individual’s capacity to work. Under the new regulation, to qualify for an exemption, a beneficiary must prove that their medical condition completely prevents them from working.

State governments state that they had spent months negotiating implementation plans with CMS prior to the publication of the regulation, but were caught unprepared by this highly restrictive definition, which they argue was not present in the legislative text.

State officials emphasize that individuals who are legally entitled to protection risk losing their health coverage because they will be unable to overcome the bureaucratic barriers imposed to prove their exempt status.

“These changes flagrantly ignore the concrete evidence that the agency was required to consider, or which was already before it,” the complaint states regarding the agency’s decision-making process. “Reasonable alternatives and potential major adverse consequences were not adequately evaluated, nor was it clarified what exactly is being demanded of the plaintiff states.”

The plaintiff states point out that Congress deliberately kept the scope of the exemptions broad when drafting the legislation.

Stressing that the broad exemptions in the law are well-founded, the complaint states: “Individuals with disabilities, patients undergoing cancer treatment, or people battling serious and complex health conditions must not be placed at risk of losing this vital care that helps them maintain their health.”

US demand for strict artificial intelligence regulation is rising, driven by a powerful bipartisan consensus that favors tighter rules for the technology, a new public opinion survey shows.

The poll, conducted by the Artificial Intelligence Policy Institute (AIPI), revealed that 68% of respondents support a requirement for the government to subject “the most advanced AI models to a formal review process before they are widely released.”

In contrast, 20% of participants expressed the view that the government should “rely primarily on companies to test their own AI models and step in mainly after problems arise.” The remaining 12% of respondents were undecided on which approach to support.

Broken down by political affiliation, the formal review process is supported by 76% of Democrats, 64% of Republicans, and 63% of independent voters.

Conversely, the survey showed that 15% of Democrats, 24% of Republicans, and 23% of independents believe the government should rely chiefly on self-testing by companies.

Backlash against data centers grows

Efforts to block or restrict the construction of data centers have gained momentum at both the state and local government levels in recent months.

Public opposition to the construction of massive AI infrastructure projects in local communities is becoming increasingly pronounced across the US.

Two months ago, the Maine State Legislature passed a bill halting the development of large-scale data centers, making it the first state in the country to take such action.

Resistance to data centers has been on the rise for the past several years. Local communities have expressed growing concern over the high energy consumption of these infrastructure facilities and their subsequent impact on the cost of living and the environment.

In March, Democratic Representative Alexandria Ocasio-Cortez and Independent Senator Bernie Sanders announced the Artificial Intelligence Data Center Moratorium Act.

The proposed legislation seeks to halt the construction of AI infrastructure until lawmakers enact measures that mandate state reviews of AI products, prevent mass job losses, and limit increases in consumer electricity prices.

The public opinion poll was conducted between June 10 and June 11 among 1,007 likely voters. The survey has a margin of error of 4.2%.