{"id":"CVE-2026-6342","title":"Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via creating groups that share the same pr…","summary":"Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via creating groups that share the same pr…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-863"],"vendor":"mattermost","product":"mattermost_server","affected":["mattermost_server >= 10.13.0, <= 10.13.11","mattermost_server >= 11.1.0, <= 11.1.5","mattermost_server >= 11.3.0, <= 11.3.4"],"published":"2026-05-18","updated":"2026-10-14","sourceUpdated":"2026-10-14T20:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-6342","references":[{"url":"https://mattermost.com/security-updates","label":"responsibledisclosure@mattermost.com"}],"tags":["nvd"],"epss":0.00254,"epssPercentile":0.15791,"ingestedAt":"2026-10-14T20:53:12.298Z","slug":"CVE-2026-6342","body":"## Overview\n\nMattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via creating groups that share the same prefix as a whitelisted group. Mattermost Advisory ID: MMSA-2026-00601\n\n## Affected\n\n- `mattermost_server >= 10.13.0, <= 10.13.11`\n- `mattermost_server >= 11.1.0, <= 11.1.5`\n- `mattermost_server >= 11.3.0, <= 11.3.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}