Vulnerability Details CVE-2026-21866
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 13.3%
CVSS Severity