CVE-2021-29972: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 1% chance of exploitation in the next 30 days.

A use-after-free vulnerability was found via testing, and traced to an out-of-date Cairo library. Updating the library resolved the issue, and may have remediated other, unknown security vulnerabilities as well. This vulnerability affects Firefox < 90.

Affected products

• Mozilla Firefox: before 90.0 (fixed in 90.0)

Published 2021-08-05. Last modified 2026-06-17.