CVE-2026-71436

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

• https://github.com/mermaid-js/mermaid/commit/630aa7e5dd417e1f56bff2a1ce8df2c5ad08d289
• https://github.com/mermaid-js/mermaid/releases/tag/mermaid%4011.16.1
• https://github.com/mermaid-js/mermaid/commit/ef60adc837d9d5107af21285f01e83dea309bd0a
• https://github.com/mermaid-js/mermaid/releases/tag/v10.9.8