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% (39th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40476?

Upgrade graphql-php to 15.31.5 or later.

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

How to fix

Remediation Available

graphql-phpNVD

Affected:< 15.31.5Fixed in:15.31.5CVE-2026-40476derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

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

39thpercentile

Low risk: more likely to be exploited than 39% of all known CVEs.

References

Vendor Advisory1

github.com

Release Notes1

github.com

Related Vulnerabilities

Other CWE-407 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-27223	Medium	5.2	78%	-	Fix
CVE-2022-36021	Medium	5.5	60%	-	Fix
CVE-2021-33582	High	7.5	3.1%	-	Fix
CVE-2024-43485	High	7.5	3.1%	-	Fix
CVE-2024-43484	High	7.5	2.9%	-	Fix
CVE-2016-10396	High	7.5	2.9%	-	-

Embed a live status badge for CVE-2026-40476

Markdown

[![CVE-2026-40476](https://tridentstack.com/cve/badge/CVE-2026-40476.svg)](https://tridentstack.com/cve/CVE-2026-40476)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-40476"><img src="https://tridentstack.com/cve/badge/CVE-2026-40476.svg" alt="CVE-2026-40476"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it works Start freeThis CVE lookup is free and always will be.

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.