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CVE

CVE-2026-30241

Mercurius's queryDepth limit bypassed for WebSocket subscriptions
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CVE

CVE-2026-30241

Mercurius's queryDepth limit bypassed for WebSocket subscriptions

Description

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.

Workarounds

Disable subscriptions and, in general, queries over the WebSocket.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
2.7
-
4.0
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
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/mercurius-js/mercurius/security/advisories/GHSA-m4h2-mjfm-mp55, https://nvd.nist.gov/vuln/detail/CVE-2026-30241, https://github.com/mercurius-js/mercurius/commit/5b56f60f4b0d60780b0ff499a479bd830bdd6986, https://github.com/mercurius-js/mercurius

Severity

8.2

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
8.2
EPSS Probability
0.0002%
EPSS Percentile
0.05617%
Introduced Version
0
Fix Available
16.8.0

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