Bug 2516177

Summary: CVE-2026-48804 python-socketio: python-socketio: Denial of Service via binary attachment accumulation [fedora-all]
Product: [Fedora] Fedora Reporter: Joel Chamberlain <jochambe>
Component: python-socketioAssignee: Ben Beasley <code>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: code, manisandro
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["d6a2edb6-5ae2-4b23-97b4-ebe1411c6af8"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Clone Of: Environment:
Last Closed: 2026-08-16 14:43:31 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2514329    

Description Joel Chamberlain 2026-08-14 20:26:41 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.

python-socketio is a Python implementation of the Socket.IO realtime client and server. The python-socketio server stores binary `EVENT` and `ACK` messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. Prior to version 5.16.4, an attacker can submit a binary message and intentionally omit sending one or more of its attachments to cause the message along with the partial list of received attachments to stay in memory for a long time. Version 5.16.4 takes the following measures to address this issue: Binary packets are only accepted from authenticated clients and, when a client disconnects, the server checks if there is a partial binary message being held for the client and deletes it.

Comment 1 Ben Beasley 2026-08-16 14:40:56 UTC
*** Bug 2516178 has been marked as a duplicate of this bug. ***

Comment 2 Ben Beasley 2026-08-16 14:43:31 UTC
The CVE is fixed in 5.16.4, which is already in all releases.