CVE-2026-63421

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 60% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
40%
KEV
Not listed

Published

August 21, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Aug 21, 2026
Patch available. Sources: github, github_pr, github_commit.
github_commit Patch Available

commit 9fb88b246950 (keystonejs/keystone)

Patch available: keystonejs/keystone 2026-07-01 (contains commit 9fb88b246950)

https://github.com/keystonejs/keystone/commit/9fb88b246950ce4de754a43fe6416f20403577b1
github_pr Patch Available

Backport enforce maxTake for negative take values

Patch available: keystonejs/keystone 2026-07-01 (PR #9859 merged 2026-07-01)

https://github.com/keystonejs/keystone/pull/9859
github Patch Available

`graphql.maxTake` bypass with negative `take` · Advisory · keystonejs/keystone · GitHub

https://github.com/keystonejs/keystone/security/advisories/GHSA-cqmq-8755-7xvh

Vendor Advisories for CVE-2026-63421(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
@keystone-6/core—6.5.3—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 49× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 04:51 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 03:59 UTCEG score recompute
  4. 2026-09-16 14:19 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-15 13:23 UTCEG score recompute
  8. 2026-09-14 00:33 UTCEG score recompute
  9. 2026-09-13 00:01 UTCEG score recompute
  10. 2026-09-11 23:26 UTCEG score recompute
  11. 2026-09-11 14:53 UTCEPSS rescore
  12. 2026-09-11 10:11 UTCEG score recompute
  13. 2026-09-11 09:37 UTCEPSS rescore
  14. 2026-09-10 09:39 UTCEG score recompute
  15. 2026-09-09 01:45 UTCEG score recompute
  16. 2026-09-08 22:01 UTCEPSS rescore
  17. 2026-09-07 18:52 UTCEG score recompute
  18. 2026-09-07 16:01 UTCEPSS rescore
  19. 2026-09-06 18:18 UTCEG score recompute
  20. 2026-09-06 13:47 UTCEPSS rescore
  21. 2026-09-05 17:45 UTCEG score recompute
  22. 2026-09-05 15:31 UTCEPSS rescore
  23. 2026-09-04 17:13 UTCEG score recompute
  24. 2026-09-04 05:07 UTCEPSS rescore
  25. 2026-09-02 15:48 UTCEG score recompute
Show 24 more
  1. 2026-09-02 14:12 UTCEPSS rescore
  2. 2026-09-01 15:08 UTCEG score recompute
  3. 2026-09-01 13:54 UTCEPSS rescore
  4. 2026-09-01 04:40 UTCEPSS rescore
  5. 2026-08-31 02:16 UTCEG score recompute
  6. 2026-08-30 19:17 UTCEPSS rescore
  7. 2026-08-30 01:42 UTCEG score recompute
  8. 2026-08-30 01:22 UTCEPSS rescore
  9. 2026-08-29 01:06 UTCEG score recompute
  10. 2026-08-28 21:42 UTCEPSS rescore
  11. 2026-08-27 19:01 UTCEG score recompute
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-26 18:24 UTCEG score recompute
  14. 2026-08-26 18:07 UTCEG score recompute
  15. 2026-08-26 14:46 UTCEPSS rescore
  16. 2026-08-25 23:38 UTCEG score recompute
  17. 2026-08-25 13:49 UTCEPSS rescore
  18. 2026-08-24 23:04 UTCEG score recompute
  19. 2026-08-24 10:48 UTCEG score recompute
  20. 2026-08-23 10:15 UTCEG score recompute
  21. 2026-08-23 00:19 UTCEPSS rescore
  22. 2026-08-21 21:24 UTCEG score recompute
  23. 2026-08-21 20:19 UTCEG score recompute
  24. 2026-08-21 20:19 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-63421?
CVE-2026-63421 is a high vulnerability published on August 21, 2026. 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…
When was CVE-2026-63421 disclosed?
CVE-2026-63421 was first published in the National Vulnerability Database on August 21, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63421 actively exploited?
CVE-2026-63421 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 60.3% of all scored CVEs.
What is the CVSS score of CVE-2026-63421?
CVE-2026-63421 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-63421?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63421, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63421

Explore →

Is Your Infrastructure Affected by CVE-2026-63421?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs