ReviewHigh

CVE-2026-63421

keystonejs keystone

Keystone is a content management system for Node.js. Prior to 6.5.3, the findMany resolver in packages/core/src/lib/core/queries/resolvers.ts compares the signed take argument directly with graphql.maxTake, allowing a remote unauthenticated GraphQL client to provide a negative take value whose magnitude exceeds the configured bound. The bypass also applies to relationship queries and can return more records than the developer intended, potentially exhausting service resources. This issue is fixed in version 6.5.3.

CVSS: 7.5
EPSS: -
CISA KEV: Not listed
Published: 2026.08.22

PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: keystonejs keystone
Affected versions: < 6.5.3
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that keystonejs keystone and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE: CWE-20, CWE-480