Input validation error in Firefox ESR - CVE-2026-8961
Published: May 19, 2026
Vulnerability identifier: #VU131845
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-8961
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Firefox ESR
Firefox ESR
Detailed vulnerability description
The vulnerability allows a remote attacker to spoof content.
The vulnerability exists due to improper input validation in the Form Autofill component when rendering crafted web content. A remote attacker can present crafted content to spoof content.
User interaction is required to visit a specially crafted website or URL.
How to mitigate CVE-2026-8961
Install security update from vendor's website.