CVE-2026-33151

socket.io allows an unbounded number of binary attachments

State
Published
Severity
8.7 High
Published
Mar 20, 2026
Updated
Mar 23, 2026
Reserved
Mar 17, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
4.08.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-20 Improper Input Validation
  • CWE-754 Improper Check for Unusual or Exceptional Conditions

Affected Products

ProductVersions
socket.iosocketio
  • < 3.3.5Affected
  • >= 3.4.0, < 3.4.4Affected
  • >= 4.0.0, < 4.2.6Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.