Mattermost Desktop App fails to restrict the allow list of domains which NTLM credentials are passed
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.2%
exploitation probability
0.2%top 91% of all CVEs
observed exploitation
nono source reports it
Mattermost Desktop App versions <=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop App which allows any user on a server without the image proxy enabled to intercept other users credentials via embedding an image that routes to an external web server. Mattermost Advisory ID: MMSA-2026-00651
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
Affected products
Mattermost · MattermostReferences
https://mattermost.com/security-updates