CVE-2025-11712

MEDIUM

Mozilla Firefox < 140.4.0 - XSS

Title source: rule
STIX 2.1

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.

Scores

CVSS v3 6.1
EPSS 0.0004
EPSS Percentile 11.9%
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