{"id":"GHSA-mxxh-fmjq-j6x4","summary":"Mattermost doesn't validate whether users were correctly owned by the correct Connected Workspace","details":"Mattermost versions 10.11.x \u003c= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API. Mattermost Advisory ID: MMSA-2026-00603.","aliases":["CVE-2026-27769","GO-2026-5522"],"modified":"2026-06-25T23:11:16.930632238Z","published":"2026-04-17T15:31:17Z","database_specific":{"cwe_ids":["CWE-862"],"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2026-04-28T23:02:16Z","nvd_published_at":"2026-04-15T11:16:33Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27769"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://mattermost.com/security-updates"}],"affected":[{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.0.0-20250721062209-4952acea88ce"},{"fixed":"8.0.0-20260316060126-bc1a2b34b1f9"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-mxxh-fmjq-j6x4/GHSA-mxxh-fmjq-j6x4.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:N"}]}