VulnerabilityModified
CVE-2025-5266
Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks.
MEDIUM 4.3EPSS 0.33%
Does this matter?
Lower severity and a low EPSS score (0.33%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- EPSS
- 0.33% probability · 26th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- mozilla/firefox
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1965628Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2025-42/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-44/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-45/
- https://www.mozilla.org/security/advisories/mfsa2025-46/
- https://lists.debian.org/debian-lts-announce/2025/05/msg00043.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.