CVE-2025-11712
MEDIUM severity · CVSS 6.1 · CWE-116
6.1CVSS MEDIUM
Summary
A malicious page could have used the type attribute of an OBJECT tag to override the default browser behavior when encountering a web resource served without a content-type. This could have contributed to an XSS on a site that unsafely serves files without a content-type header. This vulnerability was fixed in Firefox 144, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
Confidentiality impactLow
Integrity impactLow
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Affected products we track (2)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.
Additional information
- NVD record
- https://www.mozilla.org/security/advisories/mfsa2025-81/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-83/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-84/Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-85/Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1979536
- https://lists.debian.org/debian-lts-announce/2025/10/msg00015.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00031.html