Bug 2500848

Summary: CVE-2026-47736 rubygem-puma: Puma: Denial of Service due to unbounded memory growth in PROXY protocol v1 [fedora-all]
Product: [Fedora] Fedora Reporter: jkelly <jkelly>
Component: rubygem-pumaAssignee: Vít Ondruch <vondruch>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: 45CC: jaruga, pvalena, ruby-packagers-sig, vondruch
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["0a34db0b-3529-49e9-a4fb-81e2a9e64c44"]}
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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: 2500583    

Description jkelly 2026-07-15 10:13:49 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.

Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, when PROXY protocol v1 support is enabled, Puma reads incoming bytes into an internal buffer while waiting for CRLF to determine whether a PROXY v1 line is present, allowing an attacker that continuously sends bytes without CRLF to cause unbounded in-process memory growth and additional CPU cost from repeatedly scanning the growing buffer. This issue is fixed in versions 7.2.1 and 8.0.2.
Comment 1 Aoife Moloney 2026-08-17 15:20:10 UTC 
This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.