GCVE-110-VULN-PYPI-2026-000588

The notebook_payload rule (NotebookPayloadRule, on by default) tokenises the shell lines in a scanned Jupyter notebook's cells with Python's shlex: the %alias_magic arguments in _ipython_cells._define_magic_alias since 1.0.0rc2, and every shell line in _ipython_cells._shell_words, used by local_scripts, since 1.0.0rc3. shlex takes time quadratic in the length of one unquoted run, so a single long line in a notebook anywhere in a scanned tree, such as a repository, pull request, model bundle or upload, can stall a scan. Only availability is affected. Affects 1.0.0rc2 through 1.0.0rc5. Version 1.0.0 does not pass a line longer than 32 KiB to shlex: an over-long shell line or %alias_magic argument is reported as not read, and the cell's result is inconclusive.