CVE-2025-11711 is a security vulnerability in Mozilla Firefox where some JavaScript Object properties marked as non-writeable could be altered. This behavior violates expected JavaScript property immutability and could potentially be leveraged to alter application logic or security controls. The vulnerability was fixed in Firefox 144 and corresponding ESR and Thunderbird versions. The CVSS 3.1 vector indicates the vulnerability is remotely exploitable over the network without privileges, requires user interaction, and impacts integrity but not confidentiality or availability.

The vulnerability allows an attacker to modify JavaScript Object properties that should be immutable, potentially leading to integrity violations within the browser environment. While it does not directly impact confidentiality or availability, the ability to change non-writeable properties could facilitate further attacks or bypass security mechanisms. No known exploits in the wild have been reported.

A fix for this vulnerability is available and has been incorporated in Firefox 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4. Users and administrators should update to these versions or later to remediate the vulnerability. No additional mitigation actions are required beyond applying the official update.