Improper Check for Unusual or Exceptional Conditions in Mozilla products - CVE-2026-117990
Published: October 27, 2026
Vulnerability identifier: #VU158195
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-2026-117990
CWE-ID: CWE-754
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to escape browser sandbox restrictions.
The vulnerability exists due to incorrect handling of boundary conditions in the Graphics: WebRender component when rendering content. A remote attacker can trigger mishandled boundary conditions through crafted content to cross the sandbox security boundary.
Affected software
Firefox ESR
Mozilla Firefox
Firefox for Android
Mozilla Firefox
Firefox for Android
How to mitigate CVE-2026-117990
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