high8.2
CVE-2026-30241
Mercurius's queryDepth limit bypassed for WebSocket subscriptions
Impact
## 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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | mercurius | < 16.8.0 | 16.8.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mercurius Project | Mercurius | before 16.8.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/mercurius-js/mercurius/commit/5b56f60f4b0d60780b0ff499a479bd830bdd6986
- https://github.com/mercurius-js/mercurius/security/advisories/GHSA-m4h2-mjfm-mp55
- https://github.com/advisories/GHSA-m4h2-mjfm-mp55
- https://nvd.nist.gov/vuln/detail/CVE-2026-30241