{"id":"CVE-2026-6062","sourceIdentifier":"responsibledisclosure@mattermost.com","published":"2026-06-22T14:17:51.003","lastModified":"2026-06-23T20:50:26.453","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650"}],"affected":[{"source":"responsibledisclosure@mattermost.com","affectedData":[{"vendor":"Mattermost","product":"Mattermost","defaultStatus":"unaffected","versions":[{"version":"11.7.0","lessThanOrEqual":"11.7.0","versionType":"semver","status":"affected"},{"version":"11.6.0","lessThanOrEqual":"11.6.2","versionType":"semver","status":"affected"},{"version":"11.5.0","lessThanOrEqual":"11.5.5","versionType":"semver","status":"affected"},{"version":"10.11.0","lessThanOrEqual":"10.11.17","versionType":"semver","status":"affected"},{"version":"11.8.0","status":"unaffected"},{"version":"11.7.1","status":"unaffected"},{"version":"11.6.3","status":"unaffected"},{"version":"11.5.6","status":"unaffected"},{"version":"10.11.18","status":"unaffected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"responsibledisclosure@mattermost.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L","baseScore":6.4,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"LOW","availabilityImpact":"LOW"},"exploitabilityScore":1.6,"impactScore":4.7}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-06-22T15:41:30.282800Z","id":"CVE-2026-6062","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"responsibledisclosure@mattermost.com","type":"Secondary","description":[{"lang":"en","value":"CWE-639"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","versionStartIncluding":"10.11.0","versionEndExcluding":"10.11.18","matchCriteriaId":"96DE4802-EC1E-43F1-BA75-6645A6EE12FF"},{"vulnerable":true,"criteria":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","versionStartIncluding":"11.5.0","versionEndExcluding":"11.5.6","matchCriteriaId":"DE6925FD-7708-4A31-A240-087199E4A907"},{"vulnerable":true,"criteria":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","versionStartIncluding":"11.6.0","versionEndExcluding":"11.6.3","matchCriteriaId":"1D3AEA32-BA45-409E-BF12-47F253639A6E"},{"vulnerable":true,"criteria":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","versionStartIncluding":"11.7.0","versionEndExcluding":"11.7.1","matchCriteriaId":"5B5CE3FF-EE89-4013-821B-3ED4A48B4352"}]}]}],"references":[{"url":"https://mattermost.com/security-updates","source":"responsibledisclosure@mattermost.com","tags":["Vendor Advisory"]}]}