AI·
Six Claude 5 models in twelve weeks. Fable 5.1 is the first to watermark its output.
Anthropic's Fable 5.1 doubles a science benchmark and cuts cache reads 75%. Independent tests measured tasks costing up to 3x more than Fable 5.
#claude-mythos
RSSClaude Mythos Preview is Anthropic's restricted cyber model, available only through Project Glasswing. Coverage of who has access and what they're doing with it.
Security·
60 hours of AI cryptanalysis. HAWK's authors pulled it from NIST's post-quantum race.
Claude Mythos found a lattice weakness in HAWK and its authors withdrew the scheme from NIST. Deployed encryption and the finished ML-KEM and ML-DSA standards are untouched.
Policy·
The US lifted its export ban on Anthropic's Fable 5. The model returns Wednesday.
The Commerce Department cleared Claude Fable 5 and Mythos 5, ending an 18-day export-control freeze. Anthropic redeploys Fable 5 globally on Wednesday with tighter safeguards.
AI·
Days after opening Fable 5 to the public, a US government order forced Anthropic to pull it
A Commerce Department export directive forced Anthropic to disable Fable 5 and Mythos 5 for all users, days after opening Fable 5 to the public.
AI·
Claude Fable 5 is Anthropic's first public Mythos-class model. It tops SWE-Bench Pro at 80.3%.
Claude Fable 5 hits 80.3% on SWE-Bench Pro and ships on Bedrock and Copilot at $10/$50 per million tokens, free on paid plans only through June 22.
Policy·
Anthropic is sending Mythos 5, the model it called too dangerous, to cyberdefenders and the US government
Mythos 5 is the same model as Fable 5 with cyber safeguards lifted, going to Project Glasswing defenders and, Anthropic says, ~150 orgs across 15+ countries.
AI·
Anthropic's Glasswing logged 10,000 vulnerabilities in a month. Most are still waiting on a patch.
Anthropic says Project Glasswing's first month produced over 10,000 critical-and-high-severity vulns. Verification and patching is the limiting step.
AI·
A Discord group guessed Anthropic's URL pattern and walked into Claude Mythos
Bloomberg reports a small group accessed Anthropic's locked-down Mythos model the same day it launched, using credentials from a third-party contractor and educated URL guessing.
Open Source·
Mozilla fixed 271 Firefox bugs that Claude Mythos found. Its own tests caught 22.
Firefox 150 shipped Monday with 271 security fixes from Anthropic's Project Glasswing. Mozilla CTO Bobby Holley says Mythos matches elite human researchers.
AI·
NSA is running Anthropic's Mythos. The Pentagon says Anthropic is a supply-chain risk.
Axios reports the NSA is using Anthropic's unreleased Mythos model even though the Defense Department has blacklisted Anthropic. One government, two positions.
AI·
OpenAI launches GPT-5.4-Cyber for defensive security, opens access to thousands
OpenAI's new cybersecurity-tuned model can reverse-engineer binaries and analyze malware. It's restricted to verified defenders through the Trusted Access program.