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 is vulnerable to CSS injection via sibling combinator selectors generated from diagram-supplied class or id names. An attacker who can supply diagram text can inject arbitrary CSS into the rendered page, potentially altering the appearance or behavior of unrelated page elements. This issue is fixed in versions 10.9.8 and 11.16.1.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact Low

Subsequent System Integrity Impact Low

Subsequent System Availability Impact Low

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
mermaid-js mermaid affected
Version Status Constraints
< 10.9.8 affected —
>= 11.0.0-alpha.1, < 11.16.1 affected —

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

No data.

Project Subscriptions

No data.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-6x64-9x62-f2gx Mermaid allows CSS injection applying to sibling elements of the diagram
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/mermaid-js/mermaid/commit/12d472c9ed43f94814b110da8d7a9ae6dd5266ed cve-icon
https://github.com/mermaid-js/mermaid/commit/7e83f1533318b307764d961906a73377266f4c5e cve-icon
https://github.com/mermaid-js/mermaid/pull/8022 cve-icon
https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.16.1 cve-icon
https://github.com/mermaid-js/mermaid/releases/tag/v10.9.8 cve-icon
https://github.com/mermaid-js/mermaid/security/advisories/GHSA-6x64-9x62-f2gx cve-icon
History

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 is vulnerable to CSS injection via sibling combinator selectors generated from diagram-supplied class or id names. An attacker who can supply diagram text can inject arbitrary CSS into the rendered page, potentially altering the appearance or behavior of unrelated page elements. This issue is fixed in versions 10.9.8 and 11.16.1.
Title Mermaid allows CSS injection applying to sibling elements of the diagram
Weaknesses CWE-94
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-06T19:55:27.994Z

Reserved: 2026-06-03T20:54:20.432Z

Link: CVE-2026-50159

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-07T01:15:05Z

Weaknesses