CVE-2026-84640

HighCVSS 7.5/10Last modified Sep 3, 2026

Description

A maliciously constructed mail header could lead to a one byte read past the end of a buffer. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Metrics

CVSS 3.1 7.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Weakness enumeration

CWE-126

Affected software

VendorProductVersions
MozillaThunderbird—

References

Timeline

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

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CVE-2026-84640: High severity, CVSS 7.5 | Vulnix