CVE-2026-71436
Fix: mermaid-js/mermaid@630aa7eCVE-2026-71436 is a CWE-835 vulnerability in mermaid. O3 Security confirms whether CVE-2026-71436 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Mermaid XY Charts are vulnerable to an infinite loop DoS
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-71436.
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.
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
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mermaid | ≥ 10.6.0&&< 10.9.8 | 10.9.8 |
| 📦npm | mermaid | ≥ 11.0.0-alpha.1&&< 11.16.1 | 11.16.1 |
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 10.9.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-71436 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 CVE-2026-71436 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 CVE-2026-71436. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-71436 in your dependencies?
O3 detects CVE-2026-71436 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.