CVE-2026-4371 Affecting thunderbird package, versions <0:140.9.0-1.0.1.el10_1


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.36% (28th percentile)

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  • Snyk IDSNYK-ORACLE10-THUNDERBIRD-15928248
  • published8 Apr 2026
  • disclosed24 Mar 2026

Introduced: 24 Mar 2026

CVE-2026-4371  (opens in a new tab)

How to fix?

Upgrade Oracle:10 thunderbird to version 0:140.9.0-1.0.1.el10_1 or higher.
This issue was patched in ELSA-2026-6342.

NVD Description

Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird package as distributed by Oracle. See How to fix? for Oracle:10 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1