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 62% 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
Trending — 3 sources updated this week
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
38(Track)
EG Risk 38/100SSVC: 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%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

August 21, 2026

Last Modified

August 21, 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.

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 9× 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. 2026-08-25 23:38 UTCEG score recompute
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-24 23:04 UTCEG score recompute
  4. 2026-08-24 10:48 UTCEG score recompute
  5. 2026-08-23 10:15 UTCEG score recompute
  6. 2026-08-23 00:19 UTCEPSS rescore
  7. 2026-08-21 21:24 UTCEG score recompute
  8. 2026-08-21 20:19 UTCEG score recompute
  9. 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. 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 61.5% 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

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