Main Vulnerability Database Vulnerabilities #VU156064

Use-after-free in Mozilla Firefox and Firefox for Android - CVE-2026-109761

Published: October 16, 2026

Vulnerability identifier: #VU156064

CSH Severity: High

CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-109761

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to corrupt memory and potentially cause a denial of service or execute arbitrary code.

The vulnerability exists due to use-after-free in the JavaScript: WebAssembly component when processing WebAssembly operations. A remote attacker can trigger access to freed memory to corrupt browser memory, potentially causing a crash or arbitrary code execution.

Affected software

Mozilla Firefox
Firefox for Android

How to mitigate CVE-2026-109761

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