Answer in brief
CVE-2026-71437 records a Medium severity (CVSS 6.5) vulnerability in Mermaid Architecture diagrams are vulnerable to prototype pollution. The current sources do not mark it as known exploited. The current feed maps mermaid-js/mermaid (generic), mermaid (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps mermaid-js/mermaid (generic), mermaid (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| mermaid-js/mermaidgeneric | >= 11.5.0, < 11.16.1 | Not reported |
| mermaidnpm | >=11.5.0,<11.16.1 | 11.16.1 |
Published upstream
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 6, 2026
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 11.5.0 until 11.16.1, Mermaid Architecture Diagrams are vulnerable to prototype pollution when a diagram defines a group with an id of __proto__. Because the group id is used directly as an object property key without validation, an attacker who can supply diagram text can pollute Object.prototype, potentially affecting the behavior of the embedding application. This issue is fixed in version 11.16.1.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-71437 records a Medium severity (CVSS 6.5) vulnerability in Mermaid Architecture diagrams are vulnerable to prototype pollution. The current sources do not mark it as known exploited. The current feed maps mermaid-js/mermaid (generic), mermaid (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps mermaid-js/mermaid (generic), mermaid (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| mermaid-js/mermaidgeneric | >= 11.5.0, < 11.16.1 | Not reported |
| mermaidnpm | >=11.5.0,<11.16.1 | 11.16.1 |
Published upstream
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 6, 2026
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 11.5.0 until 11.16.1, Mermaid Architecture Diagrams are vulnerable to prototype pollution when a diagram defines a group with an id of __proto__. Because the group id is used directly as an object property key without validation, an attacker who can supply diagram text can pollute Object.prototype, potentially affecting the behavior of the embedding application. This issue is fixed in version 11.16.1.
Quoted source text, attributed separately from HOL analysis.