CVE-2025-5266

medium

Description

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

References

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

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

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

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

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

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

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

Details

Source: Mitre, NVD

Published: 2025-05-27

Updated: 2026-04-13

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 4.3

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