Medium severity · published Sep 25, 2026
CVE-2026-67227
RabbitMQ: Atom exhaustion: to_atom on global-parameter :name
4.9
CVSS
0.4%
EPSS
No
On KEV
Description
RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7 and 4.3.1, Atom exhaustion: toatom on global-parameter :name. resourceexists/2 (and the PUT/DELETE handlers) call rabbitdatacoercion:toatom/1 on the :name URL path segment. toatom/1 uses binarytoatom/2 (unsafe). The endpoint requires policymaker (not management, but below A user with the policymaker tag can crash the node by exhausting the atom table via repeated requests to /api/global-parameters/:name with unique :name Management plugin enabled policymaker tag ~1M HTTP. This issue is fixed in versions 4.0.22 and 4.1.14 and 4.2.7 and 4.3.1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RA
rabbitmq-server · rabbitmq
>= 4.0.0, < 4.0.22; >= 4.1.0, < 4.1.14; >= 4.2.0, < 4.2.7; >= 4.3.0, < 4.3.1 · source: vendor
RS
Rabbitmq Server · Broadcom
4.0.0 before 4.0.22; 4.1.0 before 4.1.14; 4.2.0 before 4.2.7; 4.3.0 before 4.3.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-67227
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-67227
Patch
https://github.com/rabbitmq/rabbitmq-server/commit/8fbe6d8112427e85fb9a9206b3eb6e9a3ddd3e39
Patch
https://github.com/rabbitmq/rabbitmq-server/commit/fc591e7ee27a29657ca960930acefd3e4217e007
Release Notes
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7
Release Notes
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1
Vendor Advisory
https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q7x8-97rh-cr24
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