Bug 2540101

Summary: CVE-2026-67238 rabbitmq-server: RabbitMQ: Denial of Service due to atom-table exhaustion via reply-to queue name decoding [fedora-all]
Product: [Fedora] Fedora Reporter: Jon Weiser <jweiser>
Component: rabbitmq-serverAssignee: Peter Lemenkov <lemenkov>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: lemenkov, rjones
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["495f7652-745e-402b-893a-1b52aa1e94bd"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2539723    

Description Jon Weiser 2026-09-24 14:08:49 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 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.