Description
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
Affected products
mattermost: mattermost desktop
References1
- mattermost.com/security-updates Vendor Advisory
Metrics
- CVSS 3.1
-
2.6
LOW
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N - EPSS — exploit probability
- 0% percentile: 13 · as of 8 November 2026
- CWE
- CWE-1287
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