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. Mattermost Advisory ID: MMSA-2026-00717
CVSS Details
- CVSS 3.1 Base Score: 2.6
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N)
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