Use-after-free in Mozilla products - CVE-2026-12291
Published: June 16, 2026
Vulnerability identifier: #VU134606
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-12291
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Mozilla Firefox
Firefox ESR
Firefox for Android
Mozilla Firefox
Firefox ESR
Firefox for Android
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to use-after-free in the Networking: HTTP component when handling HTTP content. A remote attacker can send crafted content to execute arbitrary code.
How to mitigate CVE-2026-12291
Install security update from vendor's website.