Review reviewHigh

CVE-2026-69185

socketio socket.io

Socket.IO enables bidirectional and low-latency communication for every platform. Prior to 4.2.7, 3.4.5, and 3.3.6, 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 vulnerability is fixed in 4.2.7, 3.4.5, and 3.3.6.

CVSS
7.5
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.08.04
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.5

Vulnerability overview

Socket.IO enables bidirectional and low-latency communication for every platform. Prior to 4.2.7, 3.4.5, and 3.3.6, 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 vulnerability is fixed in 4.2.7, 3.4.5, and 3.3.6.

Affected product and versions

Product
socketio socket.io
Affected versions
>= < 3.3.6, >= >= 3.4.0, < 3.4.5, >= >= 4.0.0, < 4.2.7
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that socketio socket.io and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
CWE-20, CWE-754