CVE-2021-41249: XSS vulnerability in GraphQL Playground

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-11-04 · updated 2026-06-17
Weakness: CWE-79

Description

GraphQL Playground is a GraphQL IDE for development of graphQL focused applications. All versions of graphql-playground-react older than graphql-playground-react@1.7.28 are vulnerable to compromised HTTP schema introspection responses or schema prop values with malicious GraphQL type names, exposing a dynamic XSS attack surface that can allow code injection on operation autocomplete. In order for the attack to take place, the user must load a malicious schema in graphql-playground. There are several ways this can occur, including by specifying the URL to a malicious schema in the endpoint query parameter. If a user clicks on a link to a GraphQL Playground installation that specifies a malicious server, arbitrary JavaScript can run in the user's browser, which can be used to exfiltrate user credentials or other harmful goals. If you are using graphql-playground-react directly in your client app, upgrade to version 1.7.28 or later.

Affected products

graphql-playground: before 1.7.28 — fixed in 1.7.28

How to fix

Upgrade to a fixed version: graphql-playground 1.7.28. Check the vendor advisory for mitigations.

References

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