Description

A malicious mail server could send malformed strings with negative lengths, causing the parser to read memory outside the buffer. If a mail server or connection to a mail server were compromised, an attacker could cause the parser to malfunction, potentially crashing Thunderbird or leaking sensitive data. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.

INFO

Published Date :

2026-03-24T20:27:15.198Z

Last Modified :

2026-04-13T13:51:25.535Z

Source :

mozilla
AFFECTED PRODUCTS

The following products are affected by CVE-2026-4371 vulnerability.

Vendors Products
Mozilla
  • Thunderbird
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-4371.

URL Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2023493 cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-4371 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-4371 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-23/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-24/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-24/#CVE-2026-4371 cve-icon
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CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
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Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact