CVE-2023-22477: Mercurius Project Mercurius

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

Mercurius is a GraphQL adapter for Fastify. Any users of Mercurius until version 10.5.0 are subjected to a denial of service attack by sending a malformed packet over WebSocket to `/graphql`. This issue was patched in #940. As a workaround, users can disable subscriptions.

Affected products

• Mercurius Project Mercurius: before 8.13.2 (fixed in 8.13.2); from 9.0.0, before 11.5.0 (fixed in 11.5.0)

Published 2023-01-09. Last modified 2026-06-17.