Main Vulnerability Database Vulnerabilities #VU156070

Race condition in Mozilla Firefox and Firefox for Android - CVE-2026-109779

Published: October 16, 2026

Vulnerability identifier: #VU156070

CSH Severity: Low

CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-109779

CWE-ID: CWE-362

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to trigger inconsistent DNS-processing state and potentially cause a denial of service.

The vulnerability exists due to a race condition in the Networking: DNS component when handling concurrent name-resolution operations. A remote attacker can trigger operations with conflicting timing to produce inconsistent state and potentially disrupt browser availability.

Affected software

Mozilla Firefox
Firefox for Android

How to mitigate CVE-2026-109779

Install security update from vendor's website.

Mozilla Firefox - update to 158.0
Firefox for Android - update to 158.0

External References

Related Security Bulletins