CVE-2025-0239 Affecting thunderbird package, versions <1:128.6.0esr-1~deb12u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.23% (14th percentile)

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  • Snyk IDSNYK-ECHOLATEST-THUNDERBIRD-18318821
  • published26 Jul 2026
  • disclosed7 Jan 2025

Introduced: 7 Jan 2025

CVE-2025-0239  (opens in a new tab)

How to fix?

Upgrade Echo:latest thunderbird to version 1:128.6.0esr-1~deb12u1 or higher.

NVD Description

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

When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

CVSS Base Scores

version 3.1