Bug 2539723 (CVE-2026-67238)

Summary: CVE-2026-67238 rabbitmq-server: RabbitMQ: Denial of Service due to atom-table exhaustion via reply-to queue name decoding
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: eglynn, jjoyce, jpretori, jschluet, lhh, mburns, mgarciac
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in RabbitMQ, a messaging and streaming broker. An authenticated AMQP (Advanced Message Queuing Protocol) client can trigger an atom-table exhaustion by sending specially crafted reply-to queue names for decoding. This can lead to the entire Erlang Virtual Machine (VM) crashing, resulting in a Denial of Service (DoS) for all connected services and users.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2540101    
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Description OSIDB Bzimport 2026-09-23 20:12:25 UTC 
RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, rabbit_pid_codec:decompose_from_binary/1 parses a caller-supplied ETF-encoded binary and calls binary_to_atom(Node, utf8) on the node-name field. It is reached from rabbit_volatile_queue:pid_from_name/2, which is invoked for any queue name / routing key beginning amq.rabbitmq.reply-to.. The CandidateNodes membership check happens after the atom is created, and the surrounding try/catch cannot reclaim atoms (they are never GC'd). binary_to_existing_atom is not used. Any authenticated AMQP client can crash the entire Erlang VM (all vhosts, all connections) with ~1M cheap requests. Preconditions include Authenticated AMQP 0-9-1 connection to any vhost No per-connection rate limit low enough to make ~1M operations infeasible. This issue is fixed in versions 4.2.7 and 4.3.1.