CVE-2026-67238 RabbitMQ: Atom-table exhaustion via reply-to queue name decoding
Authenticated attackers can crash the RabbitMQ Erlang VM by exhausting atoms via reply-to queue names, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-67238?
CVE-2026-67238 is a high-severity denial of service vulnerability in 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 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.
Weakness: CWE-400
Which versions are affected by CVE-2026-67238?
1 open source package ship an affected version, including rabbitmq.
| Package | Affected | Fixed in |
|---|---|---|
rabbitmq Bitnami | From 4.2.0 | 4.2.7, 4.3.1 |
How do I fix CVE-2026-67238?
Upgrade rabbitmq to a fixed version for your release line: 4.2.7 or 4.3.1.
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-2026-67238 being exploited?
There is no known exploitation of CVE-2026-67238 in the wild and no public exploit code.
Sources
Also known as BIT-rabbitmq-2026-67238, DEBIAN-CVE-2026-67238, GHSA-x96j-244m-mrr2, UBUNTU-CVE-2026-67238.