{"id":"GHSA-xmfh-3ccg-c9fx","summary":"Mattermost has an Incorrect Authorization issue","details":"Mattermost versions 11.7.x \u003c= 11.7.0, 10.11.x \u003c= 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669","aliases":["CVE-2026-8823"],"modified":"2026-09-22T14:45:10.458918105Z","published":"2026-06-22T18:34:16Z","database_specific":{"github_reviewed_at":"2026-09-22T14:38:49Z","nvd_published_at":"2026-06-22T16:16:42Z","cwe_ids":["CWE-863"],"severity":"LOW","github_reviewed":true},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-8823"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36487"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/7972fc53f5c0b0175879a9737308a87b42db1f0b"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/9bd77d3fc4d2af3f7f0259a205174e76a1a276e1"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/c9bf3609fb9a3e5c2de94c50742c9b91fd723e3d"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/d9a55e394cd5bc15edb49e9606bec8fec03ac4c6"},{"type":"WEB","url":"https://docs.mattermost.com/security-guide/security-updates"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v10.11.18"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v11.7.1"}],"affected":[{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.7.0"},{"fixed":"11.7.1"}]}],"versions":["11.7.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-xmfh-3ccg-c9fx/GHSA-xmfh-3ccg-c9fx.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"10.11.0"},{"fixed":"10.11.18"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-xmfh-3ccg-c9fx/GHSA-xmfh-3ccg-c9fx.json"}},{"package":{"name":"github.com/mattermost/mattermost/server/v8","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"8.0.0-20260518160100-9bd77d3fc4d2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-xmfh-3ccg-c9fx/GHSA-xmfh-3ccg-c9fx.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L"}]}