Buffer overflow in Mozilla Firefox and Firefox for Android - CVE-2026-5735
Published: April 7, 2026
Vulnerability identifier: #VU125092
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-2026-5735
CWE-ID: CWE-119
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Affected software
Mozilla Firefox
Firefox for Android
Mozilla Thunderbird
Firefox for Android
Mozilla Thunderbird
How to mitigate CVE-2026-5735
Install updates from vendor's website.
Mozilla Firefox - update to 149.0.2
Firefox for Android - update to 149.0.2
Mozilla Thunderbird - update to 149.0.2
Firefox for Android - update to 149.0.2
Mozilla Thunderbird - update to 149.0.2