CVE-2026-75588

Mattermost Desktop App versions =6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme...

CVE-2026-75588

Mattermost Desktop App versions =6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme...

CVE-2026-75588 Mattermost Desktop App plugin popout scheme validation bypass

Mattermost Desktop App versions =6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme...

PT-2026-94365

Name of the Vulnerable Software and Affected Versions Mattermost Desktop App versions prior to 6.2.2.0 Description The application fails to validate the URL scheme when verifying if a target URL is internal to the connected server. This allows a network-positioned attacker to load a plugin popout...

CVE-2026-75588: Improper Validation of Specified Type of Input

Mattermost Desktop App versions =6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme...