{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-86349","assignerOrgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","state":"PUBLISHED","assignerShortName":"Mattermost","dateReserved":"2026-09-07T09:38:22.768Z","datePublished":"2026-09-14T13:51:30.175Z","dateUpdated":"2026-09-14T19:23:01.455Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Mattermost","vendor":"Mattermost","versions":[{"lessThanOrEqual":"11.9.0","status":"affected","version":"11.9.0","versionType":"semver"},{"lessThanOrEqual":"11.8.4","status":"affected","version":"11.8.0","versionType":"semver"},{"lessThanOrEqual":"11.7.8","status":"affected","version":"11.7.0","versionType":"semver"},{"lessThanOrEqual":"10.11.22","status":"affected","version":"10.11.0","versionType":"semver"},{"version":"11.10.0","status":"unaffected"},{"version":"11.9.1","status":"unaffected"},{"version":"11.8.5","status":"unaffected"},{"version":"11.7.9","status":"unaffected"},{"version":"10.11.23","status":"unaffected"}]}],"credits":[{"lang":"en","type":"finder","value":"tr66net"}],"descriptions":[{"lang":"en","value":"Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.8, 10.11.x <= 10.11.22 fail to limit the nesting depth in the server-side Markdown parser which allows an authenticated attacker to cause a denial of service (CPU resource exhaustion) via a crafted post containing deeply nested blockquotes or list items.. Mattermost Advisory ID: MMSA-2026-00707"}],"metrics":[{"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW","version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","baseSeverity":"MEDIUM","baseScore":4.3},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","description":"CWE-407: Inefficient Algorithmic Complexity","cweId":"CWE-407"}]}],"references":[{"url":"https://mattermost.com/security-updates","name":"MMSA-2026-00707","tags":["vendor-advisory"]}],"solutions":[{"value":"Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.9, 10.11.23 or higher.","lang":"en"}],"source":{"advisory":"MMSA-2026-00707","defect":["https://mattermost.atlassian.net/browse/MM-69398"],"discovery":"EXTERNAL"},"title":"Mattermost Server Algorithmic DoS via Unbounded Markdown Block Nesting","providerMetadata":{"orgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","shortName":"Mattermost","dateUpdated":"2026-09-14T13:51:30.175Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-86349","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-09-14T19:13:43.392628Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-14T19:23:01.455Z"}}]}}