CVE-2021-38495

high

Published — · Modified —

CVSS v3

—

CVSS v2

—

VIR risk

8.0

Description

Mozilla developers reported memory safety bugs present in Thunderbird 78.13.0. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 91.1 and Firefox ESR < 91.1.

Predictions

Exploit likelihood

20%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-38495

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-38495.html

OS impact

OS	Version	Status	Fixed in
arch		fixed	`91.1.0-1`
sles		affected
debian	bookworm	fixed	`0`
debian	bullseye	fixed	`0`
debian	forky	fixed	`0`
debian	sid	fixed	`0`
debian	trixie	fixed	`0`

References

https://www.suse.com/security/cve/CVE-2021-38495.html
https://security-tracker.debian.org/tracker/CVE-2021-38495

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