CVE-2025-11712

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 144 Firefox ESR versions prior to 140.4 Thunderbird versions prior to 144 Thunderbird versions prior to 140.4

Description A malicious webpage could exploit the type attribute of an OBJECT tag to bypass standard browser security measures when handling web resources lacking a content-type header. This could lead to a cross-site scripting (XSS) attack on websites that do not securely serve files without specifying a content-type.

Recommendations Update Firefox to version 144 or later. Update Firefox ESR to version 140.4 or later. Update Thunderbird to version 144 or later. Update Thunderbird to version 140.4 or later.