GraphiQL introspection schema template injection attack

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-2021-41248: 1.26% estimated exploitation activity in the next 30 days; percentile 69.62 (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.

- 1. Impact - 2. Scope - 3. Patches - 3.1 CDN bundle implementations may be automatically patched - 4. Workarounds for Older Versions - 5. How to Re-create the Exploit - 6. Credit - 7. References - 8. For more information This is a security advisory for an XSS vulnerability in graphiql. A similar vulnerability affects graphql-playground, a fork of graphiql. There is a corresponding graphql-playground advisory and Apollo Server advisory. 1. Impact All versions of graphiql older than graphiql@1.4.7 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 vulnerable schema in graphiql. There are a number of ways that can occur. By default, the schema URL is not attacker-controllable in graphiql or in its suggested implementations or examples, leaving only very complex…

Published by the source

8 Nov 2021, 18:03 UTC

Last modified by the source

4 Feb 2026, 03:44 UTC

Source last checked

26 Oct 2026, 12:21 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-x4r7-m2q9-69c8

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-x4r7-m2q9-69c8

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# Patch Next advisory brief: CVE-2021-41248

Advisory: GraphiQL introspection schema template injection attack
IDs: CVE-2021-41248, GHSA-x4r7-m2q9-69c8
Record: https://patchnext.com/advisories/cve-2021-41248 (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: graphiql 1.4.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm graphiql: affected >= 0.5.0, < 1.4.7; fixed in 1.4.7

## Suggested inspection (read-only)
- `npm ls graphiql --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 graphiql.
- 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-x4r7-m2q9-69c8 (OSV record GHSA-x4r7-m2q9-69c8 lists affected ranges: npm graphiql >=0.5.0 <1.4.7 (fixed))
- Verified: https://github.com/advisories/GHSA-x4r7-m2q9-69c8 (GitHub-reviewed advisory GHSA-x4r7-m2q9-69c8 lists affected ranges: npm graphiql >=0.5.0 <1.4.7)

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