CVE-2025-11712

MEDIUM

Firefox < 144.0 and 140.4-140.* - Cross-Site Scripting via OBJECT Tag Type Attribute

Title source: llm

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 was fixed in Firefox 144, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.

References (7)

Core 7

Core References

Mailing List

https://lists.debian.org/debian-lts-announce/2025/10/msg00015.html

Mailing List

https://lists.debian.org/debian-lts-announce/2025/10/msg00031.html

Issue Tracking, Permissions Required

https://bugzilla.mozilla.org/show_bug.cgi?id=1979536

Vendor Advisory

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/

Scores

CVSS v3 6.1

EPSS 0.0025

EPSS Percentile 16.0%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-116

Status published

Products (7)

mozilla/firefox < 140.4.0

mozilla/firefox < 144.0

Mozilla/Firefox 140.4 - 140.*

Mozilla/Firefox 144

mozilla/thunderbird < 140.4.0

Mozilla/Thunderbird 140.4 - 140.*

Mozilla/Thunderbird 144

Published Oct 14, 2025

Tracked Since Feb 18, 2026