Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.8 and 11.16.1, Mermaid's configuration setters (mermaid.initialize, mermaidAPI.setConfig, and mermaidAPI.updateSiteConfig) merge caller-supplied configuration into Mermaid's internal config using the assignWithDepth deep-merge helper, which is vulnerable to prototype pollution. This is only exploitable if an application forwards untrusted data directly into one of these configuration entry points, which is outside their documented usage; diagram-supplied configuration (e.g. %%{init: {}}%% or YAML frontmatter) is not affected. This issue is fixed in versions 10.9.8 and 11.16.1.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-c4c3-pg64-4m4v | Mermaid configuration APIs allow prototype pollution |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 07 Aug 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Fri, 07 Aug 2026 09:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Mermaid Project
Mermaid Project mermaid |
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| Vendors & Products |
Mermaid Project
Mermaid Project mermaid |
Thu, 06 Aug 2026 22:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.8 and 11.16.1, Mermaid's configuration setters (mermaid.initialize, mermaidAPI.setConfig, and mermaidAPI.updateSiteConfig) merge caller-supplied configuration into Mermaid's internal config using the assignWithDepth deep-merge helper, which is vulnerable to prototype pollution. This is only exploitable if an application forwards untrusted data directly into one of these configuration entry points, which is outside their documented usage; diagram-supplied configuration (e.g. %%{init: {}}%% or YAML frontmatter) is not affected. This issue is fixed in versions 10.9.8 and 11.16.1. | |
| Title | Mermaid configuration APIs allow prototype pollution | |
| Weaknesses | CWE-1321 | |
| References |
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| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-07T15:40:29.335Z
Reserved: 2026-08-06T16:28:51.183Z
Link: CVE-2026-71438
Updated: 2026-08-07T15:40:24.344Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-08-07T09:00:05Z
Weaknesses
Github GHSA