CVE-2026-21866
Last modified
CVE-2026-21866 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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. EPSS estimates a 0.22% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
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
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Dify | Dify | < 1.11.2 |
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-21866?
How severe is CVE-2026-21866?
How do I fix CVE-2026-21866?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-21860Werkzeug is a comprehensive WSGI web application library. Pr…5.3
- CVE-2026-21861baserCMS is a website development framework. Prior to versio…7.2
- CVE-2026-21862RustFS is a distributed object storage system built in Rust.…7.5
- CVE-2026-21863Valkey is a distributed key-value database. Prior to version…7.5
- CVE-2026-21864Valkey-Bloom is a Rust based Valkey module which brings a Bl…7.5
- CVE-2026-21865Discourse is an open source discussion platform. In versions…6.5
- CVE-2026-21867Rejected reason: Reason: This candidate was issued in error.
- CVE-2026-21868Flag Forge is a Capture The Flag (CTF) platform. Versions 2.…7.5
- CVE-2026-21869llama.cpp is an inference of several LLM models in C/C++. In…9.8
- CVE-2026-2187A vulnerability was found in Tenda RX3 16.03.13.11. The affe…8.8
- CVE-2026-21870BACnet Protocol Stack library provides a BACnet application …5.5
- CVE-2026-21871NiceGUI is a Python-based UI framework. From versions 2.13.0…6.1
Are you affected by CVE-2026-21866?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST