CVE-2022-22761: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 0.8% chance of exploitation in the next 30 days.

Web-accessible extension pages (pages with a moz-extension:// scheme) were not correctly enforcing the frame-ancestors directive when it was used in the Web Extension's Content Security Policy. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.

Affected products

• Mozilla Firefox: before 97.0 (fixed in 97.0)
• Mozilla Firefox ESR: before 91.6 (fixed in 91.6)
• Mozilla Thunderbird: before 91.6 (fixed in 91.6)

Published 2022-12-22. Last modified 2026-06-17.