Use-after-free in Mozilla products - CVE-2026-117971
Published: October 27, 2026
Vulnerability identifier: #VU158135
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-2026-117971
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to escape the browser sandbox.
The vulnerability exists due to use-after-free in the print preview component when processing content for print preview. A remote attacker can supply crafted content that triggers access to freed memory during preview processing to cross the browser sandbox boundary.
Affected software
Mozilla Firefox
Firefox ESR
Firefox for Android
Firefox ESR
Firefox for Android
How to mitigate CVE-2026-117971
Install security update from vendor's website.
Mozilla Firefox - update to 159.0
Firefox for Android - update to 159.0
Firefox ESR - addressed in versions 115.44.0, 153.6.0
Firefox for Android - update to 159.0
Firefox ESR - addressed in versions 115.44.0, 153.6.0