CVE-2026-84639

CriticalCVSS 9.1/10Last modified Sep 3, 2026

Description

Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Metrics

CVSS 3.1 9.1/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Weakness enumeration

CWE-457

Affected software

No affected versions have been published.

Timeline

Published: Sep 1, 2026
Last modified: Sep 3, 2026
NVD status: Analyzed

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