What is CVE-2026-40476?

CVE-2026-40476 is a high-severity vulnerability in Webonyx Graphql-php, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-04-17.

How severe is CVE-2026-40476?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Webonyx Graphql-php

CVE-2026-40476

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 t…

EPSS: 0.000 (9.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Webonyx Graphql-php — versions < 15.31.5

Weakness classification (CWE)

CWE-407 — Inefficient Algorithmic Complexity

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2026-40476?: CVE-2026-40476 is a high-severity vulnerability in Webonyx Graphql-php, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-04-17.
How severe is CVE-2026-40476?: High severity. CVSS v3 base score is 7.5 out of 10.