Claude Mythos Has Found 271 Zero-Days in Firefox

2026-04-29T19:23:53Z0ba17508f73d6004cc738bef185b6a1326649be1fc99ede09e11ff9efb91a3a3
AIAnthropicBluetooth-trackingClaude MythosFirefoxGraphiteMozillaSeguritechSignalexploit-generationiOSmobile-forensicspatchesphysical-securityprivacypush-notificationssecurity-implicationsspywaresurveillancevulnerability-discoveryzero-day

What happened

Mozilla and Anthropic collaborated to scan Firefox with Anthropic’s Claude Mythos Preview, resulting in fixes for 271 security vulnerabilities included in Firefox 150. Anthropic has stated Mythos can autonomously find and weaponize vulnerabilities, raising major concerns about AI-accelerated vulnerability discovery and exploit generation; the model is not being broadly released. Related items in the feed highlight privacy and surveillance risks: the FBI extracted deleted Signal messages from an iPhone notification database (forensic leakage of secure-messaging content), a Bluetooth tracker was

Why it matters

A reviewed impact interpretation has not been published for this record.

Evidence and limitations

Source ID
schneier_blog
Record identifier
0ba17508f73d6004cc738bef185b6a1326649be1fc99ede09e11ff9efb91a3a3
Enrichment time
2026-04-29T19:23:53Z
AI-assisted enrichment
Yes

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Record · Claude Mythos Has Found 271 Zero-Days in Firefox · Baitaphish