Claude Mythos Has Found 271 Zero-Days in Firefox

2026-04-30T07:23:41Z0d3f1d2e4f11fdf5b1232b6a742f646992eb0abfa44aae6c508b8b06993c6130
ai-assisted-vulnerability-discoveryanthropicbluetooth-trackingbrowser-securityclaude-mythosdigital-forensicsexploit-generationfirefoxgraphite-spywaregruposeguritechiceiphonemodel-restrictionphysical-trackingprivacypush-notificationssignalsurveillancevulnerability-scanningzero-day

What happened

The collection highlights major security and privacy developments: Anthropic’s new model, Claude Mythos (Preview), was used to scan Firefox and identified 271 security-sensitive bugs that were fixed in Firefox 150 — and Anthropic says Mythos can autonomously find and weaponize vulnerabilities, so it is being tightly controlled. Mozilla has been using frontier AI models (e.g., Opus and Mythos) to accelerate bug-finding. Related pieces note serious operational/privacy risks: the FBI forensically extracted incoming Signal messages from an iPhone notification database even after the app was uninst

Why it matters

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

Evidence and limitations

Source ID
schneier_blog
Record identifier
0d3f1d2e4f11fdf5b1232b6a742f646992eb0abfa44aae6c508b8b06993c6130
Enrichment time
2026-04-30T07:23:41Z
AI-assisted enrichment
Yes

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