Use-After-Free Vulnerability in HTML Parser of Firefox by Mozilla
CVE-2026-124871

Currently unrated

Key Information:

Vendor: Mozilla
Status: Firefox
Vendor: CVE Published:; 10 November 2026

What is CVE-2026-124871?

A use-after-free vulnerability was discovered in the DOM's HTML Parser component of Mozilla Firefox. This flaw could potentially allow an attacker to exploit memory management issues, leading to unexpected behavior or security breaches. It has been addressed in Firefox version 160, which includes the necessary patches to mitigate the risk associated with this vulnerability.

Affected Version(s)

Firefox 160

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2079678

https://www.mozilla.org/security/advisories/mfsa2026-125/

Download the Critical Vulnerability Management Cheat Sheet

Timeline

Vulnerability published
Nov 10, 2026
Vulnerability Reserved
Nov 9, 2026

Credit

Mozilla

CVE-2026-124871 Data

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