Mermaid XY Charts are vulnerable to an infinite loop DoS

MOYENNE 5.3CVE-2026-71436 · GHSA-2v8p-3f2j-5mp7 · Published 06/08/2026 · updated 24/10/2026

En bref

CVE-2026-71436 est une vulnérabilité MOYENNE (CVSS 5.3) touchant mermaid.
Probabilité d'exploitation dans les 30 prochains jours (EPSS) : 0.58%, plus élevée que 47.9% des vulnérabilités.
Correctif : mettre à jour vers 10.9.8, 11.16.1 ou plus récent.

Package	Affected versions	Patched versions
mermaid npm	`≥ 10.6.0, < 10.9.8≥ 11.0.0-alpha.1, < 11.16.1`	`10.9.811.16.1`

Description

Impact

Mermaid XY Charts are vulnerable to an infinite loop DoS attack in the setXAxisRangeData(), when configuring an X-Axis with invalid parameters.

As each loop appends an element to an array, this would generally only cause an RangeError: Invalid array length to appear after a few seconds, but may cause the page/JavaScript process to crash due to memory exhaustion, depending on the environment.

Proof-of-concept

xychart
  x-axis 1 --> 1
  line [1, 2]

Patches

This has been patched in https://github.com/mermaid-js/mermaid/commit/630aa7e5dd417e1f56bff2a1ce8df2c5ad08d289 and released in Mermaid v11.16.1.

A backport has been made for the v10 branch in ef60adc837d9d5107af21285f01e83dea309bd0a and was released in Mermaid v10.9.8

Workarounds

There are no known workarounds. Please update to the latest version or apply the patch.

References

NVD 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.