Mitigation Bypass in Firefox ESR by Mozilla
CVE-2026-109783

Currently unrated

Key Information:

Vendor: Mozilla
Status: Firefox
Vendor: CVE Published:; 13 October 2026

What is CVE-2026-109783?

A mitigation bypass vulnerability exists in the File Handling component of Firefox ESR, enabling potential exploitation under certain conditions. The issue could allow an attacker to potentially bypass the intended security measures. This vulnerability has been addressed and resolved in Firefox ESR version 153.5, ensuring enhanced security for users.

Affected Version(s)

Firefox 153.5

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2075533

https://www.mozilla.org/security/advisories/mfsa2026-108/

Download the Critical Vulnerability Management Cheat Sheet

Timeline

Vulnerability published
Oct 13, 2026
Vulnerability Reserved
Oct 13, 2026

Credit

Mozilla

CVE-2026-109783 Data

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