{"id":"CVE-2026-9693","summary":"Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite","details":"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","modified":"2026-08-21T03:47:13.902838218Z","published":"2026-08-17T22:07:12.958Z","database_specific":{"cna_assigner":"Mattermost","cwe_ids":["CWE-459"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9693.json","unresolved_ranges":[{"extracted_events":[{"introduced":"10.11.0"},{"last_affected":"10.11.20"},{"introduced":"11.7.0"},{"last_affected":"11.7.5"}],"source":"AFFECTED_FIELD"}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9693.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9693"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"638007314e9dde1575d3caa167e1067b1c577204"},{"introduced":"a9e574a82633915f22071f0d7ca2b006f249ec2a"},{"fixed":"3e198e4d5518c09836ea4c8e7ac7201c83aab67b"}],"database_specific":{"extracted_events":[{"introduced":"10.11.0"},{"fixed":"10.11.21"},{"introduced":"11.7.0"},{"fixed":"11.7.6"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*"}}],"versions":["v11.7.5-rc1","v11.7.5","v11.7.4","v11.7.3","v10.11.20","v10.11.19","v10.11.19-rc1","v11.7.2","v10.11.18","v11.7.1","v10.11.17","v10.11.16","v11.7.0","mattermost-redux@11.7.0","@mattermost/types@11.7.0","@mattermost/shared@11.7.0","@mattermost/client@11.7.0","v10.11.15-rc1","v10.11.15","v10.11.14","v10.11.14-rc1","v10.11.13","v10.11.13-rc1","v10.11.12","v10.11.11-rc2","v10.11.11","v10.11.11-rc1","v10.11.10","v10.11.9","v10.11.9-rc1","v10.11.8","v10.11.7","v10.11.6","v10.11.5","v10.11.4-rc3","v10.11.4","v10.11.4-rc2","v10.11.4-rc1","v10.11.3","v10.11.2-rc2","v10.11.2","v10.11.2-rc1","v10.11.1","v10.11.1-rc1","v10.11.0-rc3","v10.11.0","mattermost-redux@10.11.0","@mattermost/types@10.11.0","@mattermost/client@10.11.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-9693.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N"}]}