CVE-2025-5266

MEDIUM 4.3

Script element events leaked cross-origin resource status

CVSS Score

4.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

Vendor	mozilla
Product	firefox
Ecosystems	Browser JavaScript
Industries	Technology
Published	May 27, 2025
Last Updated	Apr 13, 2026

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Affected Versions

Mozilla / Firefox

All versions affected

Mozilla / Thunderbird

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=1965628 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-42/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-44/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-45/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-46/ lists.debian.org: https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html lists.debian.org: https://lists.debian.org/debian-lts-announce/2025/05/msg00043.html

Credits

Jakub Szymsza