Bug 2540100 - CVE-2026-67220 rabbitmq-server: RabbitMQ: Denial of Service via JMS topic exchange atom exhaustion [fedora-all]
Summary: CVE-2026-67220 rabbitmq-server: RabbitMQ: Denial of Service via JMS topic exc...
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: rabbitmq-server
Version: rawhide
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Peter Lemenkov
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["135d0e4c-597c-42fa-9cef-d...
Depends On:
Blocks: CVE-2026-67220
TreeView+ depends on / blocked
 
Reported: 2026-09-24 14:08 UTC by Jon Weiser
Modified: 2026-10-09 15:45 UTC (History)
2 users (show)

Fixed In Version: rabbitmq-server-4.3.6-1.fc46 rabbitmq-server-4.3.6-1.fc45 rabbitmq-server-4.2.9-2.fc44
Clone Of:
Environment:
Last Closed: 2026-10-09 15:44:21 UTC
Type: ---
Embargoed:


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Description Jon Weiser 2026-09-24 14:08:36 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Peter Lemenkov 2026-10-09 13:24:28 UTC
This issue is already fixed upstream in RabbitMQ 4.3.6, which is the version currently built for Fedora rawhide (rabbitmq-server-4.3.6-1.fc46) and Fedora 45 (rabbitmq-server-4.3.6-1.fc45).

Fedora 44 (currently 4.2.9) and Fedora 43 (currently 4.0.9) still need attention; backports/rebases for the still-supported stable branches are being worked on. Leaving this report open to track that remaining work.

Comment 2 Peter Lemenkov 2026-10-09 15:44:21 UTC
This issue is already addressed in the rabbitmq-server builds currently shipped in all maintained Fedora branches:

  * Fedora rawhide: rabbitmq-server-4.3.6-1.fc46
  * Fedora 45:      rabbitmq-server-4.3.6-1.fc45
  * Fedora 44:      rabbitmq-server-4.2.9-2.fc44

No new build is required for these branches, so closing as CURRENTRELEASE.

Fedora 43 (rabbitmq-server-4.0.9) will NOT be updated for this CVE batch: the upstream 4.0.x line ended at 4.0.9 (later 4.0.x fixes are commercial-only, with no public OSS release) and Fedora 43 reaches end of life on 2026-12-09, so a backport to F43 is not worthwhile.


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