Buffer overflow in Mozilla Firefox and Firefox for Android - CVE-2026-84142
Published: September 1, 2026
Vulnerability identifier: #VU146631
CSH Severity: Medium
CVSS v4: 1.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-84142
CWE-ID: CWE-119
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to affect security in an unspecified manner.
The vulnerability exists due to memory corruption or another security-relevant defect in multiple unspecified components when processing crafted input. A remote attacker can trigger the underlying flaw to affect security in an unspecified manner.
The advisory describes multiple internally found bugs rather than a single fully characterized flaw.
Affected software
Mozilla Firefox
Firefox for Android
Firefox for Android
How to mitigate CVE-2026-84142
Install security update from vendor's website.
Mozilla Firefox - update to 155.0
Firefox for Android - update to 155.0
Firefox for Android - update to 155.0