CVE-2020-12406

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

Description

Mozilla Developer Iain Ireland discovered a missing type check during unboxed objects removal, resulting in a crash. We presume that with enough effort that it could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

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-2020-12406

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2020-12406.html

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202006-1

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202006-4

OS impact

OSVersionStatusFixed in
arch archfixed68.9.0-1
suse slesaffected
debian debiansidfixed77.0-1
debian debianbookwormfixed68.9.0esr-1
debian debianbullseyefixed68.9.0esr-1
debian debianforkyfixed68.9.0esr-1
debian debiantrixiefixed68.9.0esr-1

References

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