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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-677m-j7p3-52f9 socket.io allows an unbounded number of binary attachments
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 23 Mar 2026 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 23 Mar 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-770
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Moderate


Mon, 23 Mar 2026 10:00:00 +0000

Type Values Removed Values Added
First Time appeared Socket
Socket socket.io
Vendors & Products Socket
Socket socket.io

Fri, 20 Mar 2026 20:30:00 +0000

Type Values Removed Values Added
Description 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.
Title socket.io allows an unbounded number of binary attachments
Weaknesses CWE-20
CWE-754
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-23T16:50:16.998Z

Reserved: 2026-03-17T21:17:08.885Z

Link: CVE-2026-33151

cve-icon Vulnrichment

Updated: 2026-03-23T16:50:13.767Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-20T21:17:15.573

Modified: 2026-03-23T14:32:02.800

Link: CVE-2026-33151

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-20T20:13:31Z

Links: CVE-2026-33151 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-03-23T09:52:45Z

Weaknesses