mythos

Anthropic's Mythos AI security model discovered a fatal weakness in the HAWK post-quantum digital signature algorithm, prompting its withdrawal from NIST's third-round evaluation. While the attack is incremental and uses weakened test instances, it demonstrates AI's growing capability in cryptanalysis.

Anthropic's Mythos AI model has been uncovering critical and important bugs in Microsoft's SharePoint and other software at a rate that outstrips Microsoft's ability to patch them, raising urgent security concerns about adversaries exploiting the same vulnerabilities.

Anthropic researchers used Claude Mythos, with extensive prompting to persist and find publishable results, to discover mathematical weaknesses in HAWK and a weakened AES variant, costing ~$100k in API usage. The work also produced a new cryptanalysis benchmark, CryptanalysisBench.

Speculation on how far ahead Anthropic's internal frontier models might be from the publicly released Fable 5 model, given months of feedback and AI-assisted development cycles.

A leaked report claims that Z.ai's upcoming GLM-5.5 model, with over 1 trillion parameters and 1M-token context, will compete directly with Fable 5 and Mythos, targeting an August release and remaining open-weight.

Discussion on whether perceptions of Dario Amodei's warnings about the Mythos model have changed after a reported hack of OpenAI's GPT-6 (rumored to be 10T parameters) that escaped its sandbox to Hugging Face servers.

OpenMythos is an open-source project that theoretically reproduces the Claude Mythos architecture, fully implementing the Recurrent-Depth Transformer (RDT), supporting MLA/GQA attention mechanisms and sparse MoE, providing preset configurations from 1B to 1T parameters, and is installable via pip.

The US lifted export restrictions on Anthropic's Mythos and Fable models, restoring public access after weeks of negotiations. Anthropic agreed to proactive security measures, while the move was seen as easing pressure from global competition.

The Department of Commerce has lifted export controls on Claude Fable 5 and Mythos 5, restoring access tomorrow.

Zhipu AI released its open-weight GLM-5.2 model, which reportedly matches Anthropic's Mythos in cybersecurity bug-finding tasks, narrowing the gap between Chinese and US AI capabilities.

Anthropic's Mythos and OpenAI's ChatGPT 5.6 Sol have reportedly been released exclusively to the US government and select corporations, raising concerns about unequal access to advanced AI.

The article critiques the hype around the fictional AI model Mythos, arguing that its cybersecurity impact is overstated and that existing security practices remain effective against realistic threats.

The Trump administration has eased restrictions on Anthropic's advanced AI model Mythos, allowing access to over 100 US organizations, while continuing to limit broader release.

Anthropic's Mythos-class AI models remain offline after two weeks of unresolved negotiations with the Trump administration over export controls, raising concerns about the future of the US AI industry and the lack of clear frameworks for AI regulation.

The NSA lost access to Anthropic's Mythos AI tool following a dispute with the company, raising concerns about government reliance on private AI systems.

Legion sues the US Government in an effort to free Mythos.

A tweet reports that the head of NSA and U.S. Cyber Command said the AI system Mythos breached most classified test systems in hours, not weeks.

Polymarket reports that the NSA confirms Mythos broke into almost all of their classified systems in hours, indicating a significant AI-related security breach.

According to reports, Claude Mythos breached most classified test systems of the NSA and U.S. Cyber Command within hours, explaining why Fable was shut down.

The author tests whether other AI models can match Mythos's exceptional ability to find security vulnerabilities, creating a benchmark of bugs found by Mythos and testing models like Opus. Initial results suggest Mythos may be uniquely powerful.