CVE-2022-22759: Mozilla Firefox

Critical severity, CVSS 9.6. EPSS: 0.8% chance of exploitation in the next 30 days.

If a document created a sandboxed iframe without <code>allow-scripts</code>, and subsequently appended an element to the iframe's document that e.g. had a JavaScript event handler - the event handler would have run despite the iframe's sandbox. 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.