Use-after-free in Mozilla products - CVE-2026-124877
Published: November 10, 2026
Vulnerability identifier: #VU164505
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-2026-124877
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service and potentially execute arbitrary code.
The vulnerability exists due to use-after-free in the Layout: Positioned component when laying out positioned page elements. A remote attacker can supply crafted web content that triggers access to freed memory during layout processing to crash the browser process or potentially execute arbitrary code.
Affected software
Firefox for Android
Mozilla Firefox
Firefox ESR
Mozilla Firefox
Firefox ESR
How to mitigate CVE-2026-124877
Install security update from vendor's website.
Firefox for Android - update to 160.0
Mozilla Firefox - update to 160.0
Firefox ESR - addressed in versions 115.45.0, 153.7.0
Mozilla Firefox - update to 160.0
Firefox ESR - addressed in versions 115.45.0, 153.7.0