Launch Week Day 1: Announcing Security Design Review
MEDIUM 5.3 npm

Mermaid Gantt Charts are vulnerable to an Infinite Loop DoS

GHSA-6m6c-36f7-fhxh · CVE-2026-41150

Published · Modified

Description

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:

Workarounds

There are no workarounds available without updating to a newer version of mermaid.

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