SB2026091520 - Input validation error in socket.io

Description

This security bulletin contains information about 1 vulnerability.

1) Input validation error (CVE-ID: N/A)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: 8.7 [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]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper validation of protocol revision consistency in the Engine.IO transport upgrade handling when processing an upgrade request for an existing Engine.IO session. A remote attacker can establish a valid session and send an upgrade request with a different or omitted EIO query parameter to cause a denial of service.

Only servers that allow transport upgrades are affected; a crafted heartbeat packet can trigger an uncaught exception that terminates the Node.js process.

Remediation

Install update from vendor's website.

References

• https://github.com/socketio/socket.io/security/advisories/GHSA-2gc4-cqfq-p2gv
• https://github.com/socketio/socket.io/commit/86db1fc