CVE-2026-49856

Name of the Vulnerable Software and Affected Versions @jshookmcp/jshook version 0.3.1

Description The network domain implements a central Server-Side Request Forgery (SSRF) authorization policy designed to block private, loopback, link-local, and reserved targets unless explicit authorization is provided. While this policy is enforced for raw HTTP, TCP, and TLS Round Trip Time (RTT) tools, it is bypassed by the ICMP probe and traceroute tools. These specific tools resolve the target and invoke the native ICMP/traceroute sink directly without consulting the authorization policy.

An MCP client with access to an active network domain can exploit this to probe internal addresses, exposing internal reachability and route mapping from the server's network position. This allows the server to be used as an internal network probing oracle to reveal if internal hosts respond, approximate latency, and traceroute hops.

The issue involves the following functions:

Recommendations Update @jshookmcp/jshook to version 0.3.2.