CVE-2026-21866: medium-severity vulnerability in langgenius dify
Dify - Stored XSS in chat
Published · Updated
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.1epss 0.2%
exploitation probability
0.2%top 88% of all CVEs
observed exploitation
nono source reports it
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.
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
Affected products
langgenius · difyRelated CVEs — langgenius dify
In the same product, most dangerous first.
CVE-2025-58747LOWDify MCP OAuth Flow Vulnerable to XSSEPSS 5.7%CVE-2026-41948CRITICALDify v1.14.1 Path Traversal via Plugin Daemon Internal API AccessEPSS 1.9%CVE-2026-28288MEDIUMDify has a user enumeration issueEPSS 0.7%CVE-2026-41947CRITICALDify < 1.14.2 Authorization Bypass via Trace Configuration EndpointsEPSS 0.6%CVE-2026-41949HIGHDify < 1.14.2 Authorization Bypass via File Preview EndpointEPSS 0.6%CVE-2026-85021MEDIUMlanggenius dify Splash Layout splash.tsx router.replace cross site scriptingEPSS 0.5%