cvedb.io
CVE-2026-4371
HIGH · CVSS 7.4
EPSS exploitation probability: 0%
Published 2026-03-24T21:16:29.583 · Last modified 2026-06-30T03:20:32.143

Summary

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.

Affected products

mozilla — thunderbird

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.