CVE-2026-41149 (GCVE-0-2026-41149)

Vulnerability from cvelistv5 – Published: 2026-05-22 22:34 – Updated: 2026-05-23 03:22
VLAI
Title
Mermaid: Improper sanitization of `classDef` in state diagrams leads to HTML injection
Summary
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Versions 10.9.5 and earlier, as well as 11.0.0-alpha.1 through 11.14.0, are vulnerable to HTML injection under the default configuration. Specifically, the classDef directive in Mermaid state diagrams permits DOM injection that escapes the SVG context. However, <script> tags are stripped, which prevents cross-site scripting (XSS). This issue has been fixed in versions 10.9.6 and 11.15.0. If developers are unable to immediately upgrade, they can work around this issue by setting "securityLevel": "sandbox", which prevents the issue by rendering the mermaid diagram in a sandboxed <iframe>.
Severity
5.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-23 03:21 UTC
CWE
  • CWE-94 - Improper Control of Generation of Code ('Code Injection')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7814 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
mermaid-js mermaid Affected: >= 11.0.0-alpha.1, < 11.15.0
Affected: < 10.9.6
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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