CVE-2021-38496

high
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
8.0

Description

During operations on MessageTasks, a task may have been removed while it was still scheduled, resulting in memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.15, Thunderbird < 91.2, Firefox ESR < 91.2, Firefox ESR < 78.15, and Firefox < 93.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: rocky — https://errata.rockylinux.org/RLSA-2021:3755

vendor Authored 2026-05-27

Vendor advisory: rocky — https://errata.rockylinux.org/RLSA-2021:3838

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-38496

OS impact

OSVersionStatusFixed in
arch archfixed91.2.0-1
debian debiansidfixed93.0-1
debian debianbookwormfixed91.2.0esr-1
debian debianbullseyefixed78.15.0esr-1~deb11u1
debian debianforkyfixed91.2.0esr-1
debian debiantrixiefixed91.2.0esr-1
rockylinux rocky8fixed

References

Verify integrity in audit chain (admin only). AS-IS.