Use-After-Free Vulnerability in Firefox by Mozilla
CVE-2026-84118

Currently unrated

Key Information:

Vendor: Mozilla
Status: Firefox
Vendor: CVE Published:; 1 September 2026

What is CVE-2026-84118?

This vulnerability involves a use-after-free flaw in the JavaScript: GC component of Firefox, which can potentially be exploited by attackers to execute arbitrary code or cause service interruptions. Mozilla has addressed this issue in Firefox version 155 and Firefox Extended Support Release (ESR) version 153.2, highlighting the importance of updating to these versions for enhanced security.

Affected Version(s)

Firefox 153.2

Firefox 155

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2057457

https://www.mozilla.org/security/advisories/mfsa2026-82/

https://www.mozilla.org/security/advisories/mfsa2026-85/

Download the Critical Vulnerability Management Cheat Sheet

Timeline

Vulnerability published
Sep 1, 2026
Vulnerability Reserved
Sep 1, 2026

Credit

x0e

CVE-2026-84118 Data

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