CVE-2020-26972

Name: CVE-2020-26972
Creator: NVD / NIST
Published: 2021-01-07T14:15:11.813+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.29%

Last modified Jun 17, 2026

CVE-2020-26972 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 1.29% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.29%

66.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 84.0

References

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

Timeline

Published: Jan 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26972?

How severe is CVE-2020-26972?

CVE-2020-26972 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.29% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26972?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-26972?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST