CVE-2026-21866

MEDIUM EPSS 12.2%
Published Mar 3, 20263mo ago · Modified Jun 17, 20261w ago
5.1 CVSS 4.0
Medium
Find Similar
Published Mar 3, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

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 Details

Base Score
5.1
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction P
Scope X

Threat Intelligence

EPSS Exploit Probability
12.2% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

Affected Products 1

VendorProductVersionRange
difydify* <1.11.2

References 3

  • github.com https://github.com/langgenius/dify/commit/ae17537470bba417a8971fff705dd82ecb043564
    Patch
  • github.com https://github.com/langgenius/dify/pull/29811
    Issue TrackingPatch
  • github.com https://github.com/langgenius/dify/security/advisories/GHSA-qpv6-75c2-75h4
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/langgenius/dify/commit/ae17537470bba417a8971fff705dd82ecb043564
    Patch
  • github.com https://github.com/langgenius/dify/pull/29811
    Issue TrackingPatch