Mitigation Bypass in JavaScript: GC Component of Firefox by Mozilla
CVE-2026-74938

Currently unrated

Key Information:

Vendor: Mozilla
Status: Firefox
Vendor: CVE Published:; 18 August 2026

What is CVE-2026-74938?

A mitigation bypass vulnerability was identified in the JavaScript: GC component of Firefox. This loophole could potentially allow for exploitation, enabling unauthorized actions that compromise browser security. The issue was addressed with updates in Firefox 154 and Firefox ESR 153.1. Users are advised to upgrade their browsers promptly to ensure their security is maintained.

Affected Version(s)

Firefox 153.1

Firefox 154

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2053688

https://www.mozilla.org/security/advisories/mfsa2026-74/

https://www.mozilla.org/security/advisories/mfsa2026-77/

Download the Critical Vulnerability Management Cheat Sheet

Timeline

Vulnerability published
Aug 18, 2026
Vulnerability Reserved
Aug 17, 2026

Credit

Amy Burnett of OpenAI

CVE-2026-74938 Data

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