Summary
Prototype pollution vulnerability found in Mermaid's bundled version of DOMPurify
The following bundled files within the Mermaid NPM package contain a bundled version of DOMPurify that is vulnerable to https://github.com/cure53/DOMPurify/security/advisories/GHSA-mmhx-hmjr-r674, potentially resulting in an XSS attack.
This affects the built:
dist/mermaid.min.jsdist/mermaid.jsdist/mermaid.esm.mjsdist/mermaid.esm.min.mjs
This will also affect users that use the above files via a CDN link, e.g. https://cdn.jsdelivr.net/npm/[email protected]/dist/mermaid.min.js
Users that use the default NPM export of mermaid, e.g. import mermaid from 'mermaid', or the dist/mermaid.core.mjs file, do not use this bundled version of DOMPurify, and can easily update using their package manager with something like npm audit fix.
Impact
GHSA-M4GQ-X24J-JPMF has a CVSS score of 7.0 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (10.9.3); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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developbranch: 6c785c93166c151d27d328ddf68a13d9d65adc00- backport to v10: 92a07ffe40aab2769dd1c3431b4eb5beac282b34
Frequently Asked Questions
- What is GHSA-M4GQ-X24J-JPMF? GHSA-M4GQ-X24J-JPMF is a high-severity security vulnerability in mermaid (npm), affecting versions <= 10.9.2. It is fixed in 10.9.3.
- How severe is GHSA-M4GQ-X24J-JPMF? GHSA-M4GQ-X24J-JPMF has a CVSS score of 7.0 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of mermaid are affected by GHSA-M4GQ-X24J-JPMF? mermaid (npm) versions <= 10.9.2 is affected.
- Is there a fix for GHSA-M4GQ-X24J-JPMF? Yes. GHSA-M4GQ-X24J-JPMF is fixed in 10.9.3. Upgrade to this version or later.
- Is GHSA-M4GQ-X24J-JPMF exploitable, and should I be worried? Whether GHSA-M4GQ-X24J-JPMF is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-M4GQ-X24J-JPMF is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-M4GQ-X24J-JPMF? Upgrade
mermaidto 10.9.3 or later.