Bug 2541519 (CVE-2026-67227)

Summary: CVE-2026-67227 rabbitmq-server: rabbitmq-server: Denial of Service via atom exhaustion in global parameters API
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-server. An authenticated remote user with policymaker privileges can cause a Denial of Service (DoS) by sending repeated HTTP requests with unique parameter names to the global parameters API endpoint. Because user-supplied parameter names are unsafely converted into internal system identifiers (atoms) that cannot be garbage collected, the server's fixed atom table is exhausted. This resource exhaustion results in a crash of the RabbitMQ node, disrupting messaging broker availability.
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Description OSIDB Bzimport 2026-09-25 16:51:58 UTC 
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.