Improper Neutralization of Special Elements in Output Used by a Downstream Component in Mozilla products - CVE-2026-2771
Published: February 24, 2026
Vulnerability identifier: #VU123185
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-2771
CWE-ID: CWE-74
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 on the system.
The vulnerability exists due to improper input validation in the DOM: Core & HTML component. A remote attacker can execute arbitrary JavaScript code in the browser leading to a system compromise.
How to mitigate CVE-2026-2771
Install updates from vendor's website.