Unrated severityNVD Advisory· Published Sep 1, 2026

CVE-2026-84637

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.

Affected products

Mozilla Corporation/Thunderbirdllm-fuzzy
Range: <=153.2, <154

Patches

Vulnerability mechanics

References

bugzilla.mozilla.org/show_bug.cginvd
www.mozilla.org/security/advisories/mfsa2026-78/nvd
www.mozilla.org/security/advisories/mfsa2026-88/nvd

News mentions

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