CVE-2026-49856

@jshookmcp/jshook: ICMP probe and traceroute skip local-network SSRF authorization

Published Aug 13, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
@jshookmcp/jshook is an MCP server that gives AI agents tools for JavaScript analysis and security research. In version 0.3.1, he 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 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. Version 0.3.2 fixes the issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-c5r6-m4mr-8q5j @jshookmcp/jshook: ICMP probe and traceroute skip local-network SSRF authorization
History
Type Values Removed Values Added
First Time appeared Vmoranv
Vmoranv jshookmcp
Vendors & Products Vmoranv
Vmoranv jshookmcp
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description @jshookmcp/jshook is an MCP server that gives AI agents tools for JavaScript analysis and security research. In version 0.3.1, he 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 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. Version 0.3.2 fixes the issue.
Title @jshookmcp/jshook: ICMP probe and traceroute skip local-network SSRF authorization
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 13, 2026, 5:27 PM
Reserved
Jun 1, 2026, 10:03 PM
Status
Deferred
Published
Aug 13, 2026, 3:19 PM
Modified
Oct 24, 2026, 4:10 PM