XSS vulnerability in GraphQL Playground from untrusted schemas

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L

EPSS

• CVE-2021-41249: 1.22% estimated exploitation activity in the next 30 days; percentile 68.74 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

GraphQL Playground introspection schema template injection attack: Advisory Statement This is a security advisory for an XSS vulnerability in graphql-playground. A similar vulnerability affects graphiql, the package from which graphql-playground was forked. There is a corresponding graphiql advisory. - 1. Impact - 2. Scope - 3. Patches - 4. Reproducing the exploit - 5. Credit - 6. For more information 1. Impact 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…

Published by the source

8 Nov 2021, 18:06 UTC

Last modified by the source

4 Feb 2026, 04:25 UTC

Source last checked

26 Oct 2026, 12:21 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-59r9-6jp6-jcm7

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-59r9-6jp6-jcm7

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# Patch Next advisory brief: CVE-2021-41249

Advisory: XSS vulnerability in GraphQL Playground from untrusted schemas
IDs: CVE-2021-41249, GHSA-59r9-6jp6-jcm7
Record: https://patchnext.com/advisories/cve-2021-41249 (revision 2, source checked 26 Oct 2026, 12:21 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: graphql-playground-react 1.7.28. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm graphql-playground-react: affected < 1.7.28; fixed in 1.7.28

## Suggested inspection (read-only)
- `npm ls graphql-playground-react --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on graphql-playground-react.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-59r9-6jp6-jcm7 (OSV record GHSA-59r9-6jp6-jcm7 lists affected ranges: npm graphql-playground-react >=0 <1.7.28 (fixed))
- Verified: https://github.com/advisories/GHSA-59r9-6jp6-jcm7 (GitHub-reviewed advisory GHSA-59r9-6jp6-jcm7 lists affected ranges: npm graphql-playground-react >=0 <1.7.28)

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