CVE-2026-21866 describes a stored Cross-Site Scripting (XSS) vulnerability in Dify, an open-source LLM app development platform, affecting versions prior to 1.11.2. This flaw arises from Dify's default "loose" security configuration for Mermaid diagrams, allowing malicious content to execute when rendered in chats. With a CVSS score of 5.4 (Medium), this vulnerability requires low privileges and user interaction (UI:R) for exploitation, potentially leading to limited impact on confidentiality and integrity. There is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 1.11.2CPE matchmatch criteria | cpe:2.3:a:dify:dify:*:*:*:*:*:*:*:* |
CVSS version used by this source: 4.0
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
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.