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.
References
| Link | Resource |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1979536 | Issue Tracking Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2025-81/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-83/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-84/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-85/ | Vendor Advisory |
| https://lists.debian.org/debian-lts-announce/2025/10/msg00015.html | |
| https://lists.debian.org/debian-lts-announce/2025/10/msg00031.html |
Configurations
Configuration 1 (hide)
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History
23 Oct 2026, 22:10
| Type | Values Removed | Values Added |
|---|---|---|
| Summary | (es) Una página maliciosa podría haber utilizado el atributo type de una etiqueta OBJECT para anular el comportamiento predeterminado del navegador al encontrar un recurso web servido sin un content-type. Esto podría haber contribuido a un XSS en un sitio que sirve archivos de forma insegura sin una cabecera content-type. Esta vulnerabilidad afecta a Firefox < 144, Firefox ESR anterior a 140.4, Thunderbird < 144 y Thunderbird anterior a 140.4. |
18 Oct 2026, 21:10
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
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Information
Published : 2025-10-14 13:15
Updated : 2026-10-23 22:10
NVD link : CVE-2025-11712
Mitre link : CVE-2025-11712
CVE.ORG link : CVE-2025-11712
JSON object : View
Products Affected
mozilla
- firefox
- thunderbird
CWE
CWE-116
Improper Encoding or Escaping of Output