CVE-2026-55251

The NetBox Device Type Library contains a deserialization vulnerability in its test harness, which loads pull-request-controlled pickle files. An unauthenticated contributor can supply a crafted pickle file, leading to arbitrary code execution when pytest runs in GitHub Actions or in a maintainer's process.

NetBox Device Type Library in the affected repository revisions has NETBOX_DT_LIBRARY_URL in tests/test_configuration.py as a free-form tracked constant that an unauthenticated pull-request author can change before the validation test harness runs. During pytest collection, tests/definitions_test.py passes the value to Repo.clone_from and create_remote("upstream").fetch(), causing blind Git smart-HTTP requests to an attacker-selected host or loading attacker-controlled tests/known-*.json validation caches. The blind request cannot set arbitrary metadata-service headers or return response bodies, and this path does not execute remote Git hooks, but substituted known data can bypass slug, module, and rack uniqueness validation. This vulnerability is fixed in commit 8980c690097e92f5028c7e6df402b327d827ecd5.

NetBox Device Type Library, a collection of community-sourced device type definitions for import into NetBox, is vulnerable due to the absence of tests/init.py and the lack of --import-mode=importlib, causing 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 or tests/conftest.py, leading to arbitrary code execution on the GitHub Actions runner.