Use-after-free in Mozilla products - CVE-2026-100831
Published: September 29, 2026
Vulnerability identifier: #VU152864
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-2026-100831
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to crash the browser.
The vulnerability exists due to a use-after-free error in the DOM: UI Events & Focus Handling component. A remote attacker can trick the victim into visiting a specially crafted website and crash the browser.
Affected software
Mozilla Firefox
Firefox ESR
Firefox for Android
Firefox ESR
Firefox for Android
How to mitigate CVE-2026-100831
Install updates from vendor's website.
Mozilla Firefox - update to 157.0
Firefox for Android - update to 157.0
Firefox ESR - update to 153.4.0
Firefox for Android - update to 157.0
Firefox ESR - update to 153.4.0