CVE-2026-30241

LOW EPSS 28.1%
Published Mar 6, 20263mo ago · Modified Jun 17, 20261w ago
2.7 CVSS 4.0
Low
Find Similar
Published Mar 6, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

Mercurius is a GraphQL adapter for Fastify. Prior to version 16.8.0, Mercurius fails to enforce the configured queryDepth limit on GraphQL subscription queries received over WebSocket connections. The depth check is correctly applied to HTTP queries and mutations, but subscription queries are parsed and executed without invoking the depth validation. This allows a remote client to submit arbitrarily deeply nested subscription queries over WebSocket, bypassing the intended depth restriction. On schemas with recursive types, this can lead to denial of service through exponential data resolution on each subscription event. This issue has been patched in version 16.8.0.

CVSS Details

Base Score
2.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
28.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-863 Incorrect Authorization Authorization

Affected Products 1

VendorProductVersionRange
mercurius_projectmercurius* <16.8.0

References 2

  • github.com https://github.com/mercurius-js/mercurius/commit/5b56f60f4b0d60780b0ff499a479bd830bdd6986
    Patch
  • github.com https://github.com/mercurius-js/mercurius/security/advisories/GHSA-m4h2-mjfm-mp55
    Vendor Advisory

Remediation

  • github.com https://github.com/mercurius-js/mercurius/commit/5b56f60f4b0d60780b0ff499a479bd830bdd6986
    Patch