CVE-2021-29952

7.5 highEPSS 0.7%

High (7.5) in mozilla firefox. EPSS 0.7% chance of exploitation in the next 30 days.

When Web Render components were destructed, a race condition could have caused undefined behavior, and we presume that with enough effort may have been exploitable to run arbitrary code. This vulnerability affects Firefox < 88.0.1 and Firefox for Android < 88.1.3.

Severity

CVSS 3.1

7.5 high

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

EPSS: 0.7% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-31)
CWE: CWE-362
Published: 2021-06-24
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1704227
https://www.mozilla.org/security/advisories/mfsa2021-20/
https://bugzilla.mozilla.org/show_bug.cgi?id=1704227
https://www.mozilla.org/security/advisories/mfsa2021-20/

Check your stack JSON