CVE-2020-26972

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-01-07 · updated 2026-06-17
Weakness: CWE-416

Description

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

How to fix

Upgrade to a fixed version: Mozilla Firefox 84.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1671382
https://www.mozilla.org/security/advisories/mfsa2020-54/
https://bugzilla.mozilla.org/show_bug.cgi?id=1671382
https://www.mozilla.org/security/advisories/mfsa2020-54/

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