{"id":"CVE-2026-9693","aliases":["EUVD-2026-60542","GHSA-f5mp-j4vf-9jp4"],"status":"published","title":"Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite","description":"Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682","severity":{"version":"3.1","score":3.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00271,"percentile":0.19572,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-459"],"published":"2026-08-17T22:07:12Z","modified":"2026-10-28T02:30:40Z","products":[{"vendor":"mattermost","product":"mattermost"},{"vendor":"mattermost","product":"mattermost_server"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9693","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-f5mp-j4vf-9jp4"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9693.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-9693","title":"Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite","description":"Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682","status":"published","published":"2026-08-17T22:07:12.958Z","modified":"2026-08-18T14:21:04.54Z","cvss":[{"version":"3.1","score":3.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N","level":"low","assessor":"cna"}],"cwes":["CWE-459"],"updated_at":"2026-11-02T13:42:26.790871Z"}],"euvd":[{"id":"EUVD-2026-60542","description":"Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682","status":"published","published":"2026-08-17T22:07:12Z","modified":"2026-08-18T14:21:04Z","cvss":[{"version":"3.1","score":3.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N","level":"low"}],"updated_at":"2026-11-02T18:01:46.762528Z"}],"ghsa":[{"id":"GHSA-f5mp-j4vf-9jp4","title":"Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread...","description":"Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682","status":"published","published":"2026-08-18T00:30:36Z","modified":"2026-08-18T00:30:37Z","cvss":[{"version":"3.1","score":3.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N","level":"low"}],"cwes":["CWE-459"],"updated_at":"2026-11-02T15:10:35.792698Z"}],"nvd":[{"id":"CVE-2026-9693","description":"Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682","status":"published","published":"2026-08-17T23:16:52.94Z","modified":"2026-08-19T13:14:34.433Z","cvss":[{"version":"3.1","score":3.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N","level":"low","assessor":"secondary"}],"cwes":["CWE-459"],"updated_at":"2026-11-02T14:12:38.647684Z"}],"osv":[{"id":"CVE-2026-9693","title":"Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite","description":"Mattermost versions 10.11.x \u003c= 10.11.20, 11.7.x \u003c= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682","status":"published","published":"2026-08-17T22:07:12.958Z","modified":"2026-10-28T02:30:40.42032264Z","cvss":[{"version":"3.1","score":3.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N","level":"low"}],"cwes":["CWE-459"],"updated_at":"2026-11-02T15:45:21.262447Z"}]}}