Use-after-free in Mozilla Firefox and Firefox for Android - CVE-2026-118019
Published: October 27, 2026
Vulnerability identifier: #VU158222
CSH Severity: Medium
CVSS v4: 7.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-118019
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to potentially cause a denial of service or execute arbitrary code.
The vulnerability exists due to a race condition and use-after-free in Firefox's DOM: File component when handling file operations. A remote attacker can trigger unsafe operation interleavings and freed-memory access to potentially crash the process or corrupt its execution.
Affected software
Mozilla Firefox
Firefox for Android
Firefox for Android
How to mitigate CVE-2026-118019
Install security update from vendor's website.
Mozilla Firefox - update to 159.0
Firefox for Android - update to 159.0
Firefox for Android - update to 159.0