{"id":"CVE-2026-21866","summary":"Dify - Stored XSS in chat","details":"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.","aliases":["GHSA-qpv6-75c2-75h4"],"modified":"2026-04-10T05:38:34.621748Z","published":"2026-03-03T21:42:25.311Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21866.json","cwe_ids":["CWE-79"],"cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21866.json"},{"type":"ADVISORY","url":"https://github.com/langgenius/dify/security/advisories/GHSA-qpv6-75c2-75h4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21866"},{"type":"FIX","url":"https://github.com/langgenius/dify/commit/ae17537470bba417a8971fff705dd82ecb043564"},{"type":"FIX","url":"https://github.com/langgenius/dify/pull/29811"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/langgenius/dify","events":[{"introduced":"0"},{"fixed":"0c4233e7df51f146b9d007132f3aca71d36919cb"}]}],"versions":["0.10.0","0.10.1","0.10.2","0.11.0","0.11.1","0.11.2","0.12.0","0.12.1","0.13.0","0.13.1","0.13.2","0.14.0","0.14.1","0.14.2","0.15.0","0.15.1","0.15.2","0.15.3","0.2.1","0.2.2","0.3.0","0.3.1","0.3.10","0.3.11","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.28","0.3.29","0.3.3","0.3.30","0.3.31","0.3.31-fix1","0.3.31-fix2","0.3.31-fix3","0.3.32","0.3.33","0.3.34","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.4.7","0.4.8","0.4.9","0.5.0","0.5.1","0.5.10","0.5.11","0.5.11-fix1","0.5.2","0.5.3","0.5.4","0.5.5","0.5.6","0.5.7","0.5.8","0.5.9","0.6.0","0.6.0-fix1","0.6.1","0.6.10","0.6.11","0.6.12","0.6.12-fix1","0.6.13","0.6.14","0.6.15","0.6.16","0.6.2","0.6.3","0.6.4","0.6.5","0.6.6","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.7.3","0.8.0","0.8.1","0.8.2","0.8.3","0.9.0","0.9.1","0.9.2","1.0.0","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.10.0","1.10.1","1.11.0","1.11.1","1.2.0","1.3.0","1.3.1","1.4.0","1.4.1","1.4.2","1.4.3","1.5.0","1.5.1","1.6.0","1.7.0","1.7.1","1.7.2","1.8.0","1.8.1","1.9.0","1.9.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21866.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}