CVE-2026-59724
Advisory lineage Upstream: 0 Downstream: 1
Downstream
PUBLISHED
Published: 08 Jul 2026, 15:35
Last modified:08 Jul 2026, 19:41
Vulnerability Summary
Overall Risk (default)
medium
30/100 CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected
Timeline
08 Jul 2026, 15:35
Published
Vulnerability first disclosed
08 Jul 2026, 19:41
Last Modified
Vulnerability information updated
Description
Socket.IO enables bidirectional and low-latency communication for every platform. From 6.5.0 before 6.6.7, Engine.IO servers with WebTransport enabled can resolve a crafted session ID such as __proto__ through an inherited property of the clients object during WebTransport upgrade handling, causing a TypeError and denial of service. This issue is fixed in version 6.6.7.
CVSS Metrics
- v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Techniques & Countermeasures
- CWE-20•Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
Affected Systems
- socketio•socket.io
≥ 6.5.0, < 6.6.7