{"id":"GHSA-rp4v-qc77-phm4","summary":"Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel","details":"Mattermost versions 11.6.x \u003c= 11.6.1, 11.5.x \u003c= 11.5.4, 10.11.x \u003c= 10.11.15, 10.11.x \u003c= 10.11.16 fail to restrict role_updated websocket event broadcasts to members of the affected team or channel, which allows an authenticated attacker with guest-level access to observe permission scheme change notifications for private teams they are not a member of via the websocket connection. Mattermost Advisory ID: MMSA-2026-00616","aliases":["CVE-2026-3433","GO-2026-6286"],"modified":"2026-08-25T20:26:01.836424086Z","published":"2026-06-12T18:31:59Z","database_specific":{"nvd_published_at":"2026-06-12T17:16:22Z","cwe_ids":["CWE-200"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-08-24T21:30:50Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3433"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/35497"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36256"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36257"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36341"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/0a0ab0d54d899d308bd1352cc577036917500318"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/7425c6817bf244f976c729f8a73cecac8039a1e1"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/9408b98025d7364d7dfe7cdb28fcd109b1b595a6"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/a30a331a29b9766d46716d4252056d7b74e66da0"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v10.11.16"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v11.5.5"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v11.6.2"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v11.7.0"},{"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":"11.6.0"},{"fixed":"11.6.1"}]}],"versions":["11.6.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-rp4v-qc77-phm4/GHSA-rp4v-qc77-phm4.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.5.0"},{"fixed":"11.5.5"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 11.5.4","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-rp4v-qc77-phm4/GHSA-rp4v-qc77-phm4.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":"10.11.17"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 10.11.15","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-rp4v-qc77-phm4/GHSA-rp4v-qc77-phm4.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":"8.0.0-20250731163400-5b955468ea1e"},{"fixed":"8.0.0-20260504071740-9408b98025d7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-rp4v-qc77-phm4/GHSA-rp4v-qc77-phm4.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"}]}