CVE-2026-67220 RabbitMQ: JMS topic exchange erl_scan atom exhaustion

What is CVE-2026-67220?

CVE-2026-67220 is a medium-severity denial of service vulnerability in Broadcom Rabbitmq Server, published on 23 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, 4.3.0, When a binding is created on an x-jms-topic exchange, add_binding/3 reads the rjms_erlang_selector argument and passes it through erl_scan:string/1 then erl_parse:parse_term/1. erl_scan:string/1 interns every atom literal it tokenizes. validate_binding/2 is a no-op (-> ok.), there is no length cap, and the surrounding try/catch cannot reclaim atoms. The Java JMS client compiles selectors client-side, but the server does not enforce this , a raw AMQP client can send arbitrary selector strings. An authenticated low-privilege AMQP user confined to one vhost can crash the entire broker node (cross-tenant DoS) in <100 bind calls. Preconditions include rabbitmq_jms_topic_exchange plugin enabled (bundled; required for any JMS deployment) Authenticated AMQP user with read on an x-jms-topic exchange + write on a queue (or configure to declare both). This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, 4.3.0.

Weakness: CWE-400

Which versions are affected by CVE-2026-67220?

1 open source package ship an affected version, including rabbitmq. It affects 1 product.

Products include Broadcom Rabbitmq Server.

How do I fix CVE-2026-67220?

Upgrade rabbitmq to a fixed version for your release line: 3.13.15, 4.0.20, 4.1.11 or 4.2.6.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-67220 being exploited?

There is no known exploitation of CVE-2026-67220 in the wild and no public exploit code.

Other vulnerabilities in Broadcom Rabbitmq Server

• CVE-2016-9877 Auth bypass in Pivotal RabbitMQ 3.x before 3.5.8 and 3.6.x before 3.6.6; RabbitMQ for PCF 1.5.x before 1.5.20, 1.6.x before 1.6.12 and 1.7.x before 1.7.7 Critical 9.8
• CVE-2026-67404 RabbitMQ: OAuth2 silent verify_none fallback for JWKS fetch Critical 9.2
• CVE-2026-67231 RabbitMQ: Trust-store whitelist by Issuer+Serial only Critical 9.1
• CVE-2026-57219 Information disclosure in rabbitmq-server High 8.7
• CVE-2026-67236 RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login High 8.2

All Broadcom Rabbitmq Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-109725, BIT-rabbitmq-2026-67220, DEBIAN-CVE-2026-67220, GHSA-r3qr-4h63-mvj2, UBUNTU-CVE-2026-67220.