# CVE-2026-66073: RabbitMQ: Atom table exhaustion via management API node field

CVE-2026-66073 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-66073 (version 4.3.0-2), released September 26, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-66073
- Priority: Routine
- CVSS: 6.5 (Moderate)
- EPSS: 0.0047
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Weakness: Uncontrolled Resource Consumption
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66073

## Description

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6, Atom table exhaustion via management API node field. pUT /api/queues/:vhost/:name (and the exchanges and bindings endpoints) accepts a node JSON field. The value goes through rabbitnodes:make → listtoatom with no cluster membership check first. Each unique value permanently leaks one atom. A March 2026 refactoring (ea61ce2563) introduced safe helpers in rabbitmgmtnodes.erl (parsenodename, safeatom, and requirenodename, using binarytoexistingatom) and fixed several callers (QQ replica ops, wmauthattempts, wmnodememoryets, getsortreverse, and rabbitfederationmgmt), but getnode/1 in rabbitmgmtutil.erl:880-885, the primary vector used by directrequest/6, was not Roughly 900K requests crash the VM via systemlimit, and all tenants lose Any user with the management tag and one vhost, the lowest privilege This issue is fixed in versions 3.13.15 and 4.0.20 and 4.1.11 and 4.2.6.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rabbitmq-server Debian 14 | 4.3.0-2 | [DEBIAN-CVE-2026-66073](https://patchblox.com/security/data/fix/linux/debian-cve-2026-66073.md) | Sep 26, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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