{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-21866","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-01-05T16:44:16.368Z","datePublished":"2026-03-03T21:42:25.311Z","dateUpdated":"2026-03-04T21:18:08.260Z"},"containers":{"cna":{"title":"Dify - Stored XSS in chat","problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":5.1,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"}}],"references":[{"name":"https://github.com/langgenius/dify/security/advisories/GHSA-qpv6-75c2-75h4","tags":["x_refsource_CONFIRM"],"url":"https://github.com/langgenius/dify/security/advisories/GHSA-qpv6-75c2-75h4"},{"name":"https://github.com/langgenius/dify/pull/29811","tags":["x_refsource_MISC"],"url":"https://github.com/langgenius/dify/pull/29811"},{"name":"https://github.com/langgenius/dify/commit/ae17537470bba417a8971fff705dd82ecb043564","tags":["x_refsource_MISC"],"url":"https://github.com/langgenius/dify/commit/ae17537470bba417a8971fff705dd82ecb043564"}],"affected":[{"vendor":"langgenius","product":"dify","versions":[{"version":"< 1.11.2","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-03T21:43:32.391Z"},"descriptions":[{"lang":"en","value":"Dify is an open-source LLM app development platform. Prior to 1.11.2, Dify is vulnerable to a stored XSS issue when rendering Mermaid diagrams within chats. This occurs because Dify’s default Mermaid configuration uses securityLevel: loose, which allows potentially unsafe content to execute. This vulnerability is fixed in 1.11.2."}],"source":{"advisory":"GHSA-qpv6-75c2-75h4","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-04T21:17:56.778472Z","id":"CVE-2026-21866","options":[{"Exploitation":"poc"},{"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":"2026-03-04T21:18:08.260Z"}}]}}