{"id":"CVE-2026-6342","aliases":["EUVD-2026-30745","GHSA-x3f7-3cx7-2cw7"],"status":"published","title":"Group prefix matching bypass for subscriptions","description":"Mattermost Plugins versions \u003c=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","severity":{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00152,"percentile":0.04418,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-863"],"published":"2026-05-18T07:00:24Z","modified":"2026-10-14T20:10:00Z","products":[{"vendor":"mattermost","product":"mattermost"},{"vendor":"mattermost","product":"mattermost_server"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6342"},{"url":"https://github.com/advisories/GHSA-x3f7-3cx7-2cw7"}],"sources":{"cve":[{"id":"CVE-2026-6342","title":"Group prefix matching bypass for subscriptions","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-05-18T07:00:24.969Z","modified":"2026-05-18T14:32:56.965Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T13:49:53.818886Z"}],"euvd":[{"id":"EUVD-2026-30745","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-05-18T07:00:24Z","modified":"2026-05-18T14:32:56Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T18:21:16.642345Z"}],"ghsa":[{"id":"GHSA-x3f7-3cx7-2cw7","title":"Mattermost Plugins versions \u003c=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid...","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-05-18T09:31:48Z","modified":"2026-05-18T09:31:55Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:08:11.468783Z"}],"nvd":[{"id":"CVE-2026-6342","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-05-18T08:16:14.717Z","modified":"2026-10-14T20:10:00.19Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T14:12:19.39893Z"}]}}