mcp-server-semgrep/semgrep-rules/javascript/lang/security/html-in-template-string.yaml

MCP Server for Semgrep Integration - static code analysis with AI

rules:
- id: html-in-template-string
  message: >-
    This template literal looks like HTML and has interpolated variables.
    These variables are not HTML-encoded by default. If the variables contain
    HTML tags, these may be interpreted by the browser, resulting in cross-site
    scripting (XSS).
  metadata:
    cwe:
    - 'CWE-116: Improper Encoding or Escaping of Output'
    owasp:
    - A03:2021 - Injection
    category: security
    technology:
    - javascript
    subcategory:
    - audit
    likelihood: LOW
    impact: MEDIUM
    confidence: LOW
    references:
    - https://owasp.org/Top10/A03_2021-Injection
  languages:
  - javascript
  - typescript
  severity: WARNING
  patterns:
  - pattern-either:
    - pattern: |
        `$HTML${$VAR}...`
    - pattern: |
        `...${$VAR}$HTML`
  - metavariable-regex:
      metavariable: $HTML
      regex: .*</?[a-zA-Z]