Bug 2449789 (CVE-2026-33151)

Summary: CVE-2026-33151 socket.io: Socket.IO: Denial of Service due to excessive buffering of specially crafted packets
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bbrownin, gmalinko, janstey, jcantril, pdelbell, rojacob, rstepani
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in Socket.IO, an open-source, real-time communication framework. A remote attacker could exploit this vulnerability by sending specially crafted Socket.IO packets that cause the server to buffer a large number of binary attachments. This excessive buffering can lead to the server running out of memory, resulting in a Denial of Service (DoS) for legitimate users.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2450265, 2450267, 2450270, 2450272, 2450266, 2450268, 2450269, 2450271    
Bug Blocks:    

Description OSIDB Bzimport 2026-03-20 21:02:59 UTC
Socket.IO is an open source, real-time, bidirectional, event-based, communication framework. Prior to versions 3.3.5, 3.4.4, and 4.2.6, a specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory. This issue has been patched in versions 3.3.5, 3.4.4, and 4.2.6.