CVE-2026-71438

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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/mermaid-js/mermaid/commit/2cd6dcf735533b323507e3e889ffdea870540b43
https://github.com/mermaid-js/mermaid/commit/c34b07a0815842327e70794d69b0c8c5a1e2a956
https://github.com/mermaid-js/mermaid/pull/8022
https://github.com/mermaid-js/mermaid/releases/tag/mermaid%4011.16.1
https://github.com/mermaid-js/mermaid/releases/tag/v10.9.8
https://github.com/mermaid-js/mermaid/security/advisories/GHSA-c4c3-pg64-4m4v

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-06 22:18

Updated : 2026-09-08 20:53

NVD link : CVE-2026-71438

Mitre link : CVE-2026-71438

CVE.ORG link : CVE-2026-71438

JSON object : View

Products Affected

No product.

CWE

CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

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