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.
Published: 2026-09-01
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DSA Debian DSA DSA-6483-1 thunderbird security update
History

Thu, 03 Sep 2026 19:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

Thu, 03 Sep 2026 08:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 02 Sep 2026 19:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-126
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}


Wed, 02 Sep 2026 00:00:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla thunderbird
Vendors & Products Mozilla
Mozilla thunderbird

Tue, 01 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
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.
Title One byte overflow read in mail parser
References

Subscriptions

Mozilla Thunderbird
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-09-02T18:48:06.654Z

Reserved: 2026-09-01T21:33:06.555Z

Link: CVE-2026-84640

cve-icon Vulnrichment

Updated: 2026-09-02T18:47:56.768Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-01T22:17:19.800

Modified: 2026-09-03T19:01:32.800

Link: CVE-2026-84640

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-03T13:30:04Z

Weaknesses