Buffer overflow in Mozilla Firefox - CVE-2025-11721
Published: October 14, 2025
Vulnerability identifier: #VU117003
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-2025-11721
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 create a specially crafted website, trick the victim into opening it, 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
Mozilla Thunderbird
Mozilla Thunderbird
How to mitigate CVE-2025-11721
Install updates from vendor's website.
Mozilla Firefox - update to 144.0
Mozilla Thunderbird - update to 144.0
Mozilla Thunderbird - update to 144.0