CVE-2026-40476

Name: CVE-2026-40476
Creator: NVD / NIST
Published: 2026-04-17T22:16:33.36+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.9/10EPSS 0.48%

Last modified Jun 17, 2026

CVE-2026-40476 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. 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. EPSS estimates a 0.48% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

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

CVSS 4.0

6.9/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.48%

38.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-407

Affected Software

Vendor	Product	Versions
Webonyx	Graphql-Php	< 15.31.5

References

https://github.com/webonyx/graphql-php/releases/tag/v15.31.5Release Notes
https://github.com/webonyx/graphql-php/security/advisories/GHSA-68jq-c3rv-pcrrVendor Advisory

Timeline

Published: Apr 17, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-40476?

How severe is CVE-2026-40476?

CVE-2026-40476 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.48% probability of exploitation in the next 30 days.

How do I fix CVE-2026-40476?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-40476?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST