Improper Control of Generation of Code ('Code Injection') in mdx-mermaidGHSA-rvgm-35jw-q628
LOWFix: sjwall/mdx-mermaid@f2b9938GHSA-rvgm-35jw-q628 is a low-severity (CVSS 3.6) Code Injection vulnerability in mdx-mermaid. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for mdx-mermaid — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-rvgm-35jw-q628.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
mdx-mermaidnpmDescription
Impact
Arbitary javascript injection
Modify any mermaid code blocks with the following code and the code inside will execute when the component is loaded by MDXjs
` + (function () {
// Put Javascript code here
return ''
}()) + `
The block below shows a valid mermaid code block
```mermaid
graph TD;
A-->B;
A-->C;
B-->D;
C-->D;
```
The same block but with the exploit added
```mermaid
` + (function () {
alert('vulnerable')
return ''
}()) + `
graph TD;
A-->B;
A-->C;
B-->D;
C-->D;
```
Patches
1.3.0 and 2.0.0-rc2
Workarounds
None known
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mdx-mermaid | all versions | 1.3.0npm install mdx-mermaid@1.3.0 |
| 📦npm | mdx-mermaid | ≥ 2.0.0-rc1&&< 2.0.0-rc2 | 2.0.0-rc2npm install mdx-mermaid@2.0.0-rc2 |
Affected Products
mdx-mermaidmdx-mermaid_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mdx-mermaid, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mdx-mermaid to 1.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rvgm-35jw-q628 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is GHSA-rvgm-35jw-q628 in your dependencies?
Find it across npm, including transitive dependencies.