HOMEVULNERABILITIESCVE-2026-40476
MEDIUM

CVE-2026-40476

CWE-407Published: April 17, 2026· Updated: Apr 20, 2026

6.9
CVSS v3.1
EPSS:0.02%probability of exploitation in 30 daysPercentile:6.1th

Official 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.

NVD Source

Technical Analysis

CVE-2026-40476 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeX
Impact
Confidentiality
Integrity
Availability
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

Affected Vendors & Products

Mentioned vendors (from description):
Go
CPE data not yet available in NVD for this CVE.

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

All References (2)

→
https://github.com/webonyx/graphql-php/releases/tag/v15.31.5
→
https://github.com/webonyx/graphql-php/security/advisories/GHSA-68jq-c3rv-pcrr

Quick Facts

CVE IDCVE-2026-40476
CVSS Score6.9 / 10
SeverityMEDIUM
WeaknessCWE-407
CISA KEVNo
EPSS (30d)0.02%
PublishedApr 17, 2026

Related CVEs (CWE-407)

CVE-2026-43967
8.7
CVE-2026-44378
7.5
CVE-2026-34573
7.5
CVE-2026-48959
7.5
CVE-2026-41850
7.5
CVE-2026-45186
7.5

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-40476 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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