New Firefox update patches a whopping 271 bugs with help from Claude Mythos

2026-04-22 · Source: News and Advice on the World's Latest Innovations | ZDNET · Field: Technology & Digital — Software Development & Engineering, Artificial Intelligence & Machine Learning, Cybersecurity & Data Privacy · Depth: Novice, medium

Summary

Firefox 150, released on Tuesday, introduces significant enhancements to its browser features and addresses a substantial number of security vulnerabilities. Key feature updates include improved Split View functionality, allowing users to open links in a side-by-side view and search open tabs, along with better tab sharing capabilities for multiple pages. The update also adds real-time language translation via "about:translations" and an expanded built-in PDF editor that supports reordering, copying, pasting, deleting, and exporting individual pages. Critically, Firefox 150 patches 271 security bugs, with 40+ classified as severe or critical CVEs. Notably, Anthropic's Claude Mythos Preview AI model, used by Mozilla since February, played a role in identifying these flaws, including three specific CVEs (CVE-2026-6746, CVE-2026-6757, CVE-2026-6758).

Key takeaway

For security-conscious organizations and individual users, updating to Firefox 150 is imperative due to the 271 security patches, many identified with AI assistance. Your team should prioritize this update to mitigate potential risks from newly discovered vulnerabilities. Additionally, explore the enhanced Split View and PDF editing features to improve productivity within the browser, but verify the multi-tab sharing functionality as it may not work as described.

Key insights

AI models like Claude Mythos Preview can effectively identify a high volume of software vulnerabilities.

Principles

• AI accelerates vulnerability discovery.
• Regular updates are crucial for browser security.

Method

Mozilla utilized Anthropic's Claude Mythos Preview and Opus 4.6 AI models to scan Firefox code, identifying 271 security flaws, including specific CVEs, for remediation in Firefox 150.

In practice

• Update Firefox to version 150 for security fixes.
• Use Split View for side-by-side web page comparison.
• Utilize the built-in PDF editor for document management.

Topics

• Firefox 150 Update
• Security Vulnerabilities
• AI-Assisted Bug Discovery
• Claude Mythos Preview
• Project Glasswing

Best for: CTO, VP of Engineering/Data, Director of AI/ML, Software Engineer, AI Security Engineer, General Interest

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Editorial summary, takeaway, and curation by AIssential. Original article published by News and Advice on the World's Latest Innovations | ZDNET.