VulnerabilityAnalyzed

CVE-2026-40476

An attacker can send a query with thousands of repeated identical fields, causing excessive CPU usage during validation before execution begins.

MEDIUM 6.9EPSS 0.48%

Does this matter?

Lower severity and a low EPSS score (0.48%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.9 MEDIUMCVSS: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/M
EPSS: 0.48% probability · 40th percentile
CISA KEV: Not listed
Weakness: CWE-407
Affected: webonyx/graphql-php
Source: security-advisories@github.com

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

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.