CVE-2022-31744: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

An attacker could have injected CSS into stylesheets accessible via internal URIs, such as resource:, and in doing so bypass a page's Content Security Policy. This vulnerability affects Firefox ESR < 91.11, Thunderbird < 102, Thunderbird < 91.11, and Firefox < 101.

Affected products

• Mozilla Firefox: before 101.0 (fixed in 101.0)
• Mozilla Firefox ESR: before 91.11 (fixed in 91.11)
• Mozilla Thunderbird: before 91.11 (fixed in 91.11)

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