CVE-2021-38493

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

Description

Mozilla developers reported memory safety bugs present in Firefox 91 and Firefox ESR 78.13. 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 Firefox ESR < 78.14, Thunderbird < 78.14, and Firefox < 92.

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-2021:3497

vendor Authored 2026-05-27

Vendor advisory: rocky — https://errata.rockylinux.org/RLSA-2021:3499

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-38493

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-38493.html

OS impact

OSVersionStatusFixed in
arch archfixed78.14.0-1
suse slesaffected
debian debiansidfixed92.0-1
debian debianbookwormfixed78.14.0esr-1
debian debianbullseyefixed78.14.0esr-1~deb11u1
debian debianforkyfixed78.14.0esr-1
debian debiantrixiefixed78.14.0esr-1
rockylinux rocky8fixed

References

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