Input validation error in socket.io-parser - CVE-2026-33151
Published: June 25, 2026
Vulnerability identifier: #VU135350
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2026-33151
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: socket.io
Affected software:
socket.io-parser
socket.io-parser
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper input validation in the Socket.IO packet parser when processing specially crafted packets with an unbounded number of binary attachments. A remote attacker can send a specially crafted packet to cause a denial of service.
The issue can cause the server to buffer excessive binary attachments until memory is exhausted.
How to mitigate CVE-2026-33151
Install security update from vendor's website.