GHSA-6m6c-36f7-fhxh is a medium-severity (CVSS 5.3) CWE-835 vulnerability in mermaid. O3 Security confirms whether GHSA-6m6c-36f7-fhxh is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Mermaid Gantt Charts are vulnerable to an Infinite Loop DoS
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-6m6c-36f7-fhxh.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-6m6c-36f7-fhxh plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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.
mermaidnpmDescription
Impact
Mermaid v11.14.0 and earlier are vulnerable to a denial-of-service attack when rendering gantt charts, if they use the excludes attribute to exclude all dates.
Example:
gantt
excludes monday,tuesday,wednesday,thursday,friday,saturday,sunday
DoS :2025-01-01, 1d
mermaid.parse is unaffected, unless you then call the ganttDb.getTasks() (which is called when rendering a diagram).
Patches
This has been patched in:
- v11.15.0 (see faafb5d49106dd32c367f3882505f2dd625aa30e)
- v10.9.6 (see a59ea56174712ee5430dfd5bc877cb5151f501a6)
Workarounds
There are no workarounds available without updating to a newer version of mermaid.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mermaid | ≥ 11.0.0-alpha.1&&< 11.15.0 | 11.15.0 |
| 📦npm | mermaid | all versions | 10.9.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mermaid. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update mermaid to 11.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6m6c-36f7-fhxh is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-6m6c-36f7-fhxh is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-6m6c-36f7-fhxh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-6m6c-36f7-fhxh in your dependencies?
O3 detects GHSA-6m6c-36f7-fhxh across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.