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Fencer Intel
high 8.8

CVE-2026-54916 json

NetBox Device Type Library: Module Shadowing Bypass of prior pickle fix - RCE via missing `tests/__init__.py` + SSRF via unfixed `NETBOX_DT_LIBRARY_URL` → Cloud Metadata credential theft

published 5mo ago modified last mo. also EUVD-2026-82414 , GHSA-wwg5-825x-83g6

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository netbox-community/devicetype-library. 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
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

NetBox Device Type Library is a collection of community-sourced device type definitions for import into NetBox. The absence of tests/init.py and the lack of --import-mode=importlib cause pytest prepend import mode to place the tests directory at the front of sys.path during collection. An unauthenticated contributor can add a module such as tests/git.py that shadows GitPython when tests/definitions_test.py executes from git import Git, Repo, or add tests/conftest.py for automatic collection-time execution. Python imports and runs the pull-request module before any test function, allowing arbitrary code execution on the GitHub Actions runner, test-result tampering, and access to tokens or network resources exposed to the workflow. This module-shadowing path is independent of the earlier pickle deserialization flaw and the separately tracked NETBOX_DT_LIBRARY_URL issue. This vulnerability is fixed by commit b0d9a3dadd0a0a9d3c93b0b2777559fd4bad1037.

Patch / fix

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • netbox-community devicetype-library

Classification

Weakness
  • CWE-427 Uncontrolled Search Path Element
  • CWE-829 Inclusion of Functionality from Untrusted Control Sphere

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 netbox-community/devicetype-library published their own advisory on GitHub. Reviewed sources take precedence over it.