{"id":"CVE-2025-11777","state":"PUBLISHED","title":"Cross-team channel membership access","description":"Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint","publishedAt":"2025-11-13T17:32:03.975Z","updatedAt":"2025-11-13T18:01:46.459Z","severity":{"score":3.1,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","source":"Mattermost"},"assigner":"Mattermost","products":["Mattermost Mattermost"],"affected":[{"vendor":"Mattermost","product":"Mattermost","defaultStatus":"unaffected","versions":[{"version":"10.11.0","status":"affected","lessThanOrEqual":"10.11.3","versionType":"semver"},{"version":"10.5.0","status":"affected","lessThanOrEqual":"10.5.11","versionType":"semver"},{"version":"11.0.0","status":"unaffected"},{"version":"10.11.4","status":"unaffected"},{"version":"10.5.12","status":"unaffected"}]}],"references":["https://mattermost.com/security-updates"],"weaknesses":["CWE-863"],"ingestedAt":"2026-10-29T20:08:31.050Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/11xxx/CVE-2025-11777.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-11777","state":"PUBLISHED","datePublished":"2025-11-13T17:32:03.975Z","dateUpdated":"2025-11-13T18:01:46.459Z","assignerShortName":"Mattermost","assignerOrgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","dateReserved":"2025-10-15T11:37:25.782Z"},"containers":{"cna":{"title":"Cross-team channel membership access","descriptions":[{"lang":"en","value":"Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint"}],"affected":[{"vendor":"Mattermost","product":"Mattermost","defaultStatus":"unaffected","versions":[{"version":"10.11.0","status":"affected","lessThanOrEqual":"10.11.3","versionType":"semver"},{"version":"10.5.0","status":"affected","lessThanOrEqual":"10.5.11","versionType":"semver"},{"version":"11.0.0","status":"unaffected"},{"version":"10.11.4","status":"unaffected"},{"version":"10.5.12","status":"unaffected"}]}],"references":[{"url":"https://mattermost.com/security-updates"}],"metrics":[{"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE","version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","baseSeverity":"LOW","baseScore":3.1},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-863","lang":"en","type":"CWE","description":"CWE-863: Incorrect Authorization"}]}],"providerMetadata":{"shortName":"Mattermost","orgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","dateUpdated":"2025-11-13T17:32:03.975Z"},"credits":[{"lang":"en","type":"finder","value":"Xiangyu Guo"}],"solutions":[{"value":"Update Mattermost to versions 11.0.0, 10.11.4, 10.5.12 or higher.","lang":"en"}],"source":{"advisory":"MMSA-2025-00518","defect":["https://mattermost.atlassian.net/browse/MM-64661"],"discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-11-13T18:01:38.258075Z","id":"CVE-2025-11777","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-11-13T18:01:46.459Z"}}]}}}