CVE-2025-0239

4.0 MEDIUM

Published: January 07, 2025 Modified: April 13, 2026

Description

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.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

CVSS v3.x Details

0.0 Low Medium High Critical 10.0

Vector String

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

https://bugzilla.mozilla.org/show_bug.cgi?id=1929156

Source: security@mozilla.org

Issue Tracking Permissions Required

https://www.mozilla.org/security/advisories/mfsa2025-01/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2025-02/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2025-04/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2025-05/

Source: security@mozilla.org

Vendor Advisory

https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html

Source: af854a3a-2127-422b-91ae-364da2661108

6 reference(s) from NVD

Quick Stats

CVSS v3 Score

4.0 / 10.0

EPSS (Exploit Probability)

0.0%

9th percentile

Exploitation Status

Not in CISA KEV

Weaknesses (CWE)

CWE-295

Affected Vendors

mozilla

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