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TI-2026-36760 Aliases CVE-2026-49856GHSA-c5r6-m4mr-8q5j

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

Priority MEDIUM 53CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-918 and the CVSS impact.

Summary

@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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00281 20th percentileScored 2026-11-07
Fix Fixed @jshookmcp/jshook (npm): 0.3.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
vmoranvjshookmcp= 0.3.1—No fix listedCNA
—@jshookmcp/jshook (npm)0.3.1 to before 0.3.20.3.2Patch availableGHSA-c5r6-m4mr-8q5j
  • jshookmcp Vendorvmoranv Affected = 0.3.1 Fixed in — No fix listed CNA
  • @jshookmcp/jshook (npm) Vendor— Affected 0.3.1 to before 0.3.2 Fixed in 0.3.2 Patch available GHSA-c5r6-m4mr-8q5j

Remediation

  • Fix · GHSA-c5r6-m4mr-8q5j @jshookmcp/jshook (npm) Fixed in 0.3.2 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-49856
  2. 2026-10-03 Alias added: GHSA-c5r6-m4mr-8q5j

References

Other 3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences