CVE-2023-22477 — Mercurius is a GraphQL adapter for Fastify

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.

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
mercurius-js	mercurius	< 10.5.0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-01-09T14:12:24.837Z
• Last modified: 2025-03-10T21:31:05.984Z

09References

• github.com — https://github.com/mercurius-js/mercurius/security/advisories/GHSA-cm8h-q92v-xcf…
• github.com — https://github.com/mercurius-js/mercurius/issues/939
• github.com — https://github.com/mercurius-js/mercurius/pull/940