Vulnerability Details CVE-2026-18256
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private teams to disclose the ID, name, and display name of private teams via a modified team search request. Mattermost Advisory ID: MMSA-2026-00748
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 5.3%
CVSS Severity
CVSS v3 Score 4.3
References
Products affected by CVE-2026-18256
-
cpe:2.3:a:mattermost:mattermost_server:11.10.0
-
cpe:2.3:a:mattermost:mattermost_server:11.7.0
-
cpe:2.3:a:mattermost:mattermost_server:11.7.1
-
cpe:2.3:a:mattermost:mattermost_server:11.7.2
-
cpe:2.3:a:mattermost:mattermost_server:11.7.3
-
cpe:2.3:a:mattermost:mattermost_server:11.7.4
-
cpe:2.3:a:mattermost:mattermost_server:11.7.5
-
cpe:2.3:a:mattermost:mattermost_server:11.7.6
-
cpe:2.3:a:mattermost:mattermost_server:11.7.7
-
cpe:2.3:a:mattermost:mattermost_server:11.7.8
-
cpe:2.3:a:mattermost:mattermost_server:11.7.9
-
cpe:2.3:a:mattermost:mattermost_server:11.8.0
-
cpe:2.3:a:mattermost:mattermost_server:11.8.1
-
cpe:2.3:a:mattermost:mattermost_server:11.8.2
-
cpe:2.3:a:mattermost:mattermost_server:11.8.3
-
cpe:2.3:a:mattermost:mattermost_server:11.8.4
-
cpe:2.3:a:mattermost:mattermost_server:11.8.5
-
cpe:2.3:a:mattermost:mattermost_server:11.9.0
-
cpe:2.3:a:mattermost:mattermost_server:11.9.1