CVE-2026-84637

Critical · CVSS 9.8

CVSS: 9.8; nvd
EPSS: —
KEV: No
Class: other; CWE-434

Description

Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2043878
https://www.mozilla.org/security/advisories/mfsa2026-78/
https://www.mozilla.org/security/advisories/mfsa2026-88/

Status: profiled · ingested 2026-09-04T00:00:49.000Z