CVE-2026-67226

Undergoing Analysis Undergoing Analysis - In Progress

Admin-Triggered Atom Exhaustion in RabbitMQ

Publication date: 2026-09-25

Last updated on: 2026-09-28

Assigner: GitHub, Inc.

Description

RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7, Admin-only atom exhaustion: PUT /api/users tags list. settags/2 maps rabbitdatacoercion:toatom/1 over the user's tags list. The 20 MB management body limit fits ~3-4M short tag strings. An administrator can crash the node in a single request by creating a user (or importing definitions) with ~1M unique tag administrator. This issue is fixed in versions 4.0.22 and 4.1.14 and 4.2.7.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-25

Last Modified

2026-09-28

Generated

2026-10-16

AI Q&A

2026-09-25

EPSS Evaluated

2026-10-14

NVD

CVE-2026-67226

EUVD

EUVD-2026-87234

Affected Vendors & Products

Vendor	Product	Version / Range
rabbitmq	rabbitmq	From 4.0.0 (inc) to 4.0.22 (inc)
rabbitmq	rabbitmq	4.1.14
rabbitmq	rabbitmq	4.2.7

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-400	The product does not properly control the allocation and maintenance of a limited resource.

Attack-Flow Graph

Executive Summary

This vulnerability in RabbitMQ allows an administrator to crash the node by sending a large number of unique tag strings in a single request. The issue occurs when creating or modifying a user with approximately 1 million unique tags, which causes an atom exhaustion attack due to the processing of these tags.

Detection Guidance

This vulnerability can be detected by checking the RabbitMQ version and monitoring for unexpected crashes or high memory usage. Commands like 'rabbitmqctl status' or 'rabbitmq-diagnostics status' can help verify the version. Ensure the node is running versions 4.0.22, 4.1.14, or 4.2.7 or later.

Impact Analysis

An attacker with admin privileges could exploit this to crash the RabbitMQ node, leading to service disruption and potential data loss. This could affect messaging and streaming operations dependent on RabbitMQ.

Compliance Impact

This vulnerability allows an administrator to crash RabbitMQ nodes via atom exhaustion, potentially causing denial-of-service conditions. Such disruptions could impact data availability and integrity, which may violate compliance requirements under GDPR (data availability) and HIPAA (system availability for protected health information).

Mitigation Strategies

Upgrade RabbitMQ to version 4.0.22, 4.1.14, or 4.2.7 or later to address the atom exhaustion issue in the management plugin.

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