CVE-2026-2800: Mozilla Firefox

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

Spoofing issue in the WebAuthn component in Firefox for Android. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

Affected products

• Mozilla Firefox: before 148.0 (fixed in 148.0)
• Mozilla Thunderbird: before 148.0 (fixed in 148.0)

Published 2026-02-24. Last modified 2026-06-17.