CVE-2026-66067Network attack vectorHinoki check available

Authenticated service exhaustion via skipped connection-limit checks

Published Sep 23, 2026 · Updated Sep 23, 2026

Resource exhaustion in RabbitMQ Server 4.2.0 through 4.2.6 and 4.3.0 allows remote authenticated users to interrupt broker service. The rabbit_stream_reader open handler checks vhost access but omits the node, vhost, and user connection-limit checks applied to AMQP connections. With rabbitmq_stream enabled and operator limits configured, authenticated tenants can open excessive port 5552 connections and exhaust file descriptors or scheduler capacity.

CVSS severity6.0
Medium
EPSS probability0.35%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Resource exhaustion in RabbitMQ Server 4.2.0 through 4.2.6 and 4.3.0 allows remote authenticated users to interrupt broker service. The rabbit_stream_reader open handler checks vhost access but omits the node, vhost, and user connection-limit checks applied to AMQP connections. With rabbitmq_stream enabled and operator limits configured, authenticated tenants can open excessive port 5552 connections and exhaust file descriptors or scheduler capacity.

The record

CVE
CVE-2026-66067
Published
Sep 23, 2026
Updated
Sep 23, 2026
Vendor
RabbitMQ
Product
RabbitMQ Server
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 2026Record 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=>= 4.2.0, < 4.2.7
  2. Affected versionversion=>= 4.3.0, < 4.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

RabbitMQ · RabbitMQ Serverversion=>= 4.2.0, < 4.2.7; version=>= 4.3.0, < 4.3.1

Published CVSS scores

6.0RabbitMQCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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