CVE-2023-22477Public exploitNetwork attack vector

Unauthenticated server crash via unhandled WebSocket frame

Published Jan 9, 2023 · Updated Mar 10, 2025

An uncaught exception in Mercurius subscriptions before 8.13.2 and 9.0.0 through 11.4.0 allows remote attackers to crash GraphQL servers. A client that negotiates graphql-ws on /graphql can send a malformed WebSocket frame with reserved bits set, and the unhandled socket error terminates the Node.js process. Subscriptions must be enabled and reachable; no authentication or user interaction is required, and the bounded consequence is a server crash.

CVSS severity5.3
Medium
EPSS probability1.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An uncaught exception in Mercurius subscriptions before 8.13.2 and 9.0.0 through 11.4.0 allows remote attackers to crash GraphQL servers. A client that negotiates graphql-ws on /graphql can send a malformed WebSocket frame with reserved bits set, and the unhandled socket error terminates the Node.js process. Subscriptions must be enabled and reachable; no authentication or user interaction is required, and the bounded consequence is a server crash.

The record

CVE
CVE-2023-22477
Published
Jan 9, 2023
Updated
Mar 10, 2025
Vendor
mercurius-js
Product
Mercurius
Classifications
CWE-248, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 10.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

mercurius-js · Mercuriusversion=< 10.5.0

Published CVSS scores

5.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-248Uncaught Exception
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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