CVE-2020-26972: Mozilla Firefox

Critical severity, CVSS 9.8. EPSS: 1.3% chance of exploitation in the next 30 days.

The lifecycle of IPC Actors allows managed actors to outlive their manager actors; and the former must ensure that they are not attempting to use a dead actor they have a reference to. Such a check was omitted in WebGL, resulting in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 84.

Affected products

• Mozilla Firefox: before 84.0 (fixed in 84.0)

Published 2021-01-07. Last modified 2026-06-17.