Code Injection in mermaid - CVE-2026-41149
Published: May 12, 2026
Vulnerability identifier: #VU131135
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-41149
CWE-ID: CWE-94
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to inject HTML into the DOM.
The vulnerability exists due to improper sanitization in the state diagram classDef handling when rendering user-supplied state diagrams. A remote attacker can supply a specially crafted diagram definition to inject HTML into the DOM.
Under the default configuration, the injected content can escape the SVG context, and user interaction is required.
Affected software
mermaid
How to mitigate CVE-2026-41149
Install security update from vendor's website.
mermaid - addressed in versions 10.9.6, 11.15.0