CVE-2026-71438 (GCVE-0-2026-71438)

Vulnerability from cvelistv5 – Published: 2026-08-06 19:59 – Updated: 2026-08-07 15:40
VLAI
Title
Mermaid configuration APIs allow prototype pollution
Summary
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.
Severity
2.4 (Low)
CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:A/VC:N/VI:L/VA:L/SC:H/SI:H/SA:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-07 15:40 UTC
CWE
  • CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7974 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
mermaid-js mermaid Affected: < 10.9.8
Affected: >= 11.0.0-alpha.1, < 11.16.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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