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Fencer Vulns
medium 6.5

CVE-2026-67238 json

RabbitMQ: Atom-table exhaustion via reply-to queue name decoding

published 2026-09-23 46 d ago modified 2026-10-30 9 d ago also BIT-rabbitmq-2026-67238 , EUVD-2026-85624 , GHSA-x96j-244m-mrr2

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami rabbitmq 4.2.7, 4.3.1
  • vmware rabbitmq 4.2.7, 4.3.1
  • pivotal_software rabbitmq 4.2.7, 4.3.1
  • rabbitmq-server Debian 14 4.3.2-1

debian advisories DEBIAN-CVE-2026-67238

  • rabbitmq-server Ubuntu 22.04 LTS 3.9.27-0ubuntu0.6
  • rabbitmq-server Ubuntu 24.04 LTS 3.12.1-1ubuntu1.7
  • rabbitmq-server Ubuntu 26.04 LTS 4.0.5-10ubuntu5.2
  • rabbitmq-server Ubuntu Pro 16.04 LTS 3.5.7-1ubuntu0.16.04.4+esm3
  • rabbitmq-server Ubuntu Pro 18.04 LTS 3.6.10-1ubuntu0.5+esm1
  • rabbitmq-server Ubuntu Pro 20.04 LTS 3.8.3-0ubuntu0.3+esm2

ubuntu advisories UBUNTU-CVE-2026-67238

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rabbitmq-server4.3 hummingbird 1 4.3.6-1.hum1

red hat advisories RHSA-2026:67552

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-67238 updated cvss 6.5

rabbitmq-server: RabbitMQ: Denial of Service due to atom-table exhaustion via reply-to queue name decoding

  • Red Hat Hardened Images rabbitmq-server4.2 4.2.9-0.2.hum1
    affected: workaround, no fix planned “Restrict AMQP access to trusted clients until an updated build is deployed.”
  • Red Hat OpenStack Platform 18.0 rabbitmq-server
    affected: workaround, no fix available “Restrict AMQP access to trusted clients until an updated build is deployed.”
  • Red Hat Hardened Images rabbitmq-server4.3 4.3.6-1.hum1
    fixed: vendor fix “Restrict AMQP access to trusted clients until an updated build is deployed.” RHSA-2026:67552
  • Red Hat OpenStack Platform 13 (Queens) rabbitmq-server Red Hat OpenStack Platform 16.2 rabbitmq-server Red Hat OpenStack Platform 17.1 rabbitmq-server
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
46 d ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami rabbitmq
>=4.2.0, <4.2.7
>=4.3.0, <4.3.1
4.2.7
4.3.1

Affected products

  • rabbitmq rabbitmq-server

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.