A vulnerability, which was classified as problematic , has been found in Mattermost Desktop App up to 5.4.13/6.0.1/6.1.x . Affected by this vulnerability is the function window.close . The manipulation leads to improper check for unusual conditions. This vulnerability is listed as CVE-2026-4643 . The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.