CVE-2026-84637

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.

• CWE-434

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

Published

Sep 1, 2026

Last Modified

Sep 3, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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