CVE-2026-6779 is a medium severity vulnerability affecting the JavaScript Engine component of Mozilla Firefox. It was fixed in Firefox 150 as part of a broader set of security fixes addressing multiple memory safety and other issues. The CVSS vector (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N) indicates that the vulnerability can be exploited remotely without privileges or user interaction, resulting in limited confidentiality impact but no integrity or availability impact. The vendor advisory confirms the fix is included in Firefox 150 and Thunderbird 150 releases.

The vulnerability could potentially allow an attacker to gain limited access to confidential information due to the low confidentiality impact indicated by the CVSS score. There is no impact on integrity or availability. No known exploits in the wild have been reported. The vulnerability is one among many fixed in Firefox 150 and Thunderbird 150, which addressed several high and moderate impact issues as well.

Mozilla has released an official fix for this vulnerability in Firefox 150 and Thunderbird 150. Users and administrators should update to these versions or later to remediate the issue. Since this is not a cloud service, remediation depends on applying the vendor's official patch. Patch status is confirmed by the vendor advisory. No additional mitigation actions are indicated by the vendor.