@jshookmcp/jshook: ICMP probe and traceroute skip local-network SSRF authorization
Date: 2026-07
Affected: npm/@jshookmcp/jshook
Attack vector: ssrf
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-49856
CWE: CWE-918
CVSS: 4.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)

## Summary The network domain has a central SSRF authorization policy that blocks private, loopback, link-local, and reserved targets unless an explicit authorization object allows private network access. The policy is enforced by raw HTTP/TCP/TLS RTT tools, but the ICMP probe and traceroute tools resolve the target and invoke the native ICMP/traceroute sink directly. An MCP client with access to an active network domain can therefore ask the jshookmcp server to probe internal addresses such as 10.0.0.1 even when local SSRF access is disabled for the other raw network tools. This exposes an internal reachability and route mapping primitive from the server network position. ## Affected code Current main https://github.com/vmoranv/jshookmcp/commit/d309c395738638e384c28c0f599b47b2213ab595 and npm package @jshookmcp/jshook 0.3.1 both contain the issue. - src/server/domains/network/handlers/raw-latency-handlers.ts:61-66: network_rtt_measure parses optional authorization and calls resolveAuthorizedTransportTarget before probing. - src/server/domains/network/handlers/raw-latency-handlers.ts:185-190: network_latency_stats uses the same authorization guard. - src/server/domains/network/handlers/raw-latency-handlers.ts:123-139: network_traceroute resolves target with resolveHostname and calls traceroute without an authorization policy check. - src/server/domains/network/handlers/raw-latency-handlers.ts:240-257: network_icmp_probe resolves target with resolveHostname and calls icmp


Mitigations:

Architectural layers (MAESTRO):