{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-26230","assignerOrgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","state":"PUBLISHED","assignerShortName":"Mattermost","dateReserved":"2026-02-13T10:39:47.088Z","datePublished":"2026-03-16T20:19:51.287Z","dateUpdated":"2026-03-17T13:37:17.914Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Mattermost","vendor":"Mattermost","versions":[{"lessThanOrEqual":"10.11.10","status":"affected","version":"10.11.0","versionType":"semver"},{"version":"11.4.0","status":"unaffected"},{"version":"10.11.11","status":"unaffected"}]}],"credits":[{"lang":"en","type":"finder","value":"hackit_bharat"}],"descriptions":[{"lang":"en","value":"Mattermost versions 10.11.x <= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531"}],"metrics":[{"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N","baseSeverity":"LOW","baseScore":3.8},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","description":"CWE-863: Incorrect Authorization","cweId":"CWE-863"}]}],"references":[{"url":"https://mattermost.com/security-updates","name":"MMSA-2025-00531","tags":["vendor-advisory"]}],"solutions":[{"value":"Update Mattermost to versions 11.4.0, 10.11.11 or higher.","lang":"en"}],"source":{"advisory":"MMSA-2025-00531","defect":["https://mattermost.atlassian.net/browse/MM-66091"],"discovery":"EXTERNAL"},"title":"Team Admin Privilege Escalation to Demote Members to Guest","providerMetadata":{"orgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","shortName":"Mattermost","dateUpdated":"2026-03-16T20:19:51.287Z"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-17T13:37:10.650822Z","id":"CVE-2026-26230","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-17T13:37:17.914Z"}}]}}