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Fencer Intel
medium 5.9

CVE-2026-57207 json

NetBox MCP Server: HTTP transport exposes all NetBox data without authentication

published 4mo ago modified 12d ago also EUVD-2026-108992 , GHSA-5qg7-j8mr-9477

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository netboxlabs/netbox-mcp-server. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

NetBox MCP Server is a simple read-only Model Context Protocol server for NetBox. Prior to version 1.2.1, when running with TRANSPORT=http, the MCP server has no authentication on the HTTP endpoint. Any client that can reach the port gets a valid MCP session and full access to all four NetBox tools - no token or credential needed. This issue has been patched in version 1.2.1.

Patch / fix

Is CVE-2026-57207 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
12d ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/netboxlabs/netbox-mcp-server/security/advisories/GHSA-5qg7-j8mr-9477 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • netboxlabs netbox-mcp-server

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality
  • CWE-1059 Insufficient Technical Documentation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of netboxlabs/netbox-mcp-server published their own advisory on GitHub. Reviewed sources take precedence over it.