CVE-2020-12397

critical
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
9.5

Description

By encoding Unicode whitespace characters within the From email header, an attacker can spoof the sender email address that Thunderbird displays. This vulnerability affects Thunderbird < 68.8.0.

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-2020-12397

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202005-7

OS impact

OSVersionStatusFixed in
arch archfixed68.8.0-1
debian debianbookwormfixed1:68.8.0-1
debian debianbullseyefixed1:68.8.0-1
debian debianforkyfixed1:68.8.0-1
debian debiansidfixed1:68.8.0-1
debian debiantrixiefixed1:68.8.0-1

References

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