Improper Check for Unusual or Exceptional Conditions in Mozilla products - CVE-2026-117961
Published: October 27, 2026
Vulnerability identifier: #VU158173
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-117961
CWE-ID: CWE-754
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to potentially disrupt browser operation.
The vulnerability exists due to incorrect handling of boundary conditions in the Layout: Text and Fonts component when laying out text. A remote attacker can supply crafted content to trigger unexpected behavior that may disrupt browser operation.
Affected software
Firefox ESR
Mozilla Firefox
Firefox for Android
Mozilla Firefox
Firefox for Android
How to mitigate CVE-2026-117961
Install security update from vendor's website.
Firefox ESR - update to 153.6.0
Firefox for Android - update to 159.0
Mozilla Firefox - update to 159.0
Firefox for Android - update to 159.0
Mozilla Firefox - update to 159.0