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 affects Firefox < 144, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.
History

Wed, 15 Oct 2025 14:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-116
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 15 Oct 2025 12:30:00 +0000

Type Values Removed Values Added
Title thunderbird: firefox: An OBJECT tag type attribute overrode browser behavior on web resources without a content-type
Weaknesses CWE-436
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

threat_severity

Moderate


Tue, 14 Oct 2025 13:00:00 +0000

Type Values Removed Values Added
Description 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 affects Firefox < 144, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2025-10-14T12:27:35.544Z

Updated: 2025-10-15T13:28:24.592Z

Reserved: 2025-10-13T19:50:07.919Z

Link: CVE-2025-11712

cve-icon Vulnrichment

Updated: 2025-10-15T13:21:56.248Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-10-14T13:15:37.447

Modified: 2025-10-15T14:15:40.860

Link: CVE-2025-11712

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-10-14T12:27:35Z

Links: CVE-2025-11712 - Bugzilla