Protection mechanism failure in Mozilla products - CVE-2026-117864
Published: October 27, 2026
Vulnerability identifier: #VU158143
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-2026-117864
CWE-ID: CWE-693
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 insufficient isolation in the Form Manager component when handling forms. A remote attacker can trigger crafted form-related behavior to cross the sandbox security boundary.
Affected software
Firefox ESR
Mozilla Firefox
Firefox for Android
Mozilla Firefox
Firefox for Android
How to mitigate CVE-2026-117864
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