CVE-2025-5266

4.3 MEDIUM

Published: May 27, 2025 Modified: November 03, 2025

Description

Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.

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:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

https://bugzilla.mozilla.org/show_bug.cgi?id=1965628

Source: security@mozilla.org

Permissions Required

https://www.mozilla.org/security/advisories/mfsa2025-42/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2025-44/

Source: security@mozilla.org

Vendor Advisory

https://www.mozilla.org/security/advisories/mfsa2025-45/

Source: security@mozilla.org

https://www.mozilla.org/security/advisories/mfsa2025-46/

Source: security@mozilla.org

https://lists.debian.org/debian-lts-announce/2025/05/msg00043.html

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

https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html

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

7 reference(s) from NVD

Quick Stats

CVSS v3 Score

4.3 / 10.0

EPSS (Exploit Probability)

0.1%

19th percentile

Exploitation Status

Not in CISA KEV

Weaknesses (CWE)

CWE-200

Affected Vendors

mozilla

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