CVE intelligence and bounded remediation

CVE-2020-4038 — GraphQL Playground (graphql-playground-html NPM package) before version 1.6.22 have a severe XSS Reflection attack vulnerability

High CVSS 7.4

GraphQL Playground (graphql-playground-html NPM package) before version 1.6.22 have a severe XSS Reflection attack vulnerability. All unsanitized user input passed into renderPlaygroundPage() method could trigger this vulnerability. This has been patched in graphql-playground-html version 1.6.22. Note that some of the associated dependent middleware packages are also affected including but not limited to graphql-playground-middleware-express before version 1.7.16, graphql-playground-middleware-koa before version 1.6.15, graphql-playground-middleware-lambda before version 1.7.17, and graphql-playground-middleware-hapi before 1.6.13.

Severity
High
CVSS
7.4 (3.1)
Published
2020-06-08
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-79

Affected products

  • prisma / graphql-playground-html
  • prisma / graphql-playground-middleware-express
  • prisma / graphql-playground-middleware-hapi
  • prisma / graphql-playground-middleware-koa
  • prisma / graphql-playground-middleware-lambda

Matched remediation archetype

Cross-site scripting and unsafe browser output

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Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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