Is CVE-2026-40476 in the CISA KEV catalog?

No. CVE-2026-40476 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-40476?

CVE-2026-40476 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-40476?

CVE-2026-40476 has an EPSS score of 0.48% (38th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-40476

HIGH

7.5

CVSS v3

NVD

Description

graphql-go is a Go implementation of GraphQL. In versions 15.31.4 and below, the OverlappingFieldsCanBeMerged validation rule performs O(n²) pairwise comparisons of fields sharing the same response name. An attacker can send a query with thousands of repeated identical fields, causing excessive CPU usage during validation before execution begins. This is not mitigated by existing QueryDepth or QueryComplexity rules. This issue has been fixed in version 15.31.5.

CWE-407

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.48%probability of exploitation in 30 days

38thpercentile

Low risk: more likely to be exploited than 38% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-21.