CVE-2026-71437

Published: Aug 6, 2026Modified: Sep 8, 2026

6.5

Vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XShow less

Source: security-advisories@github.com (Secondary)

Description

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.

Related CWEs

CWE-1321

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

The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

References (5)

https://github.com/mermaid-js/mermaid/commit/99af3fc35ef0a9a9c8c6314521344d67523ddccf

Source: security-advisories@github.com

https://github.com/mermaid-js/mermaid/pull/8022

Source: security-advisories@github.com

https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.16.1

Source: security-advisories@github.com

https://github.com/mermaid-js/mermaid/security/advisories/GHSA-3rrr-jr9j-h3q3

Source: security-advisories@github.com

https://github.com/mermaid-js/mermaid/security/advisories/GHSA-3rrr-jr9j-h3q3

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

Timeline

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