pip-cve-gate 0.2.0

Pre-install CVE gate for pip — blocks vulnerable and freshly published packages before install

pip-cve-gate

Pre-install CVE gate for pip. Blocks vulnerable and freshly published packages before any code runs on your machine.

safe-pip install flask requests django
# [pip-cve-gate] Scanning 3 package(s)…
# [pip-cve-gate] Resolved 27 package(s) (incl. transitive deps)
# [pip-cve-gate] All clear — delegating to pip

If a package is blocked:

safe-pip install somelib
# [pip-cve-gate] BLOCKED — install aborted
#   [CVE] 'somelib==1.2.3' has known vulnerabilities: GHSA-xxxx-yyyy-zzzz
#   [FRESH_HOLD] 'dep==0.0.1' was published 1d ago (hold: 3d). Use --skip-fresh-hold to override.

Exit code 0 = clean, 1 = blocked, 2 = error.

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Why

Post-install tools (pip-audit, safety) run after pip has already downloaded and potentially executed install scripts. By then it's too late for zero-hour supply chain attacks.

pip has no native plugin hook for pre-install scanning. pip-cve-gate fills that gap with a wrapper that resolves the full dependency tree, scans every package against three independent feeds, and only delegates to real pip when everything is clean.

The closest prior art — pipask — checks PyPI advisories but lacks freshness hold and OSSF malicious package coverage. pip-cve-gate covers all three.

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What it checks

Signal	Source	Fail behaviour
Known CVEs / advisories	OSV.dev + PyPI Advisory DB	Block
OSSF malicious packages	ossf/malicious-packages	Block
Freshness hold (default 3d)	PyPI upload timestamp	Block (overridable)

Network failures fail open — a broken feed never blocks your CI.

Known limitations

• Version resolution is not pip-compatible. For unversioned specs (safe-pip install flask), the gate scans the latest release on PyPI, not the version pip would actually pick under your existing constraints. Pin or use a requirements file with explicit specifiers (flask==3.0.0 or flask>=3,<4) when you need the scan to match what pip will install.
• Environment markers are evaluated in the current interpreter. A dep gated by sys_platform == "win32" scanned on Linux will be skipped, just as pip would skip it.
• PyPI JSON API has a 60 req/min rate limit. Caching dedups transitive lookups, but very large dep graphs may still hit it. Set GITHUB_TOKEN to lift the OSSF feed's 60 req/hour limit.

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Usage

safe-pip is a drop-in replacement for pip install:

safe-pip install flask
safe-pip install "django>=4.2" "celery==5.3.6"
safe-pip install -r requirements.txt
safe-pip install flask --skip-fresh-hold   # bypass freshness hold only

Non-install subcommands pass through to real pip unchanged:

safe-pip list
safe-pip show flask
safe-pip uninstall flask

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Install

pip install pip-cve-gate

Homebrew (macOS / Linux):

brew install sharkyger/tap/pip-cve-gate

Or run directly from the repo without installing:

git clone https://github.com/sharkyger/pip-cve-gate
cd pip-cve-gate
python bin/safe-pip install flask

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Configuration

Variable	Default	Description
PIP_CVE_GATE_FRESH_HOLD_DAYS	3	Days a new release must age before install (max 365)
PIP_CVE_GATE_TIMEOUT	10	HTTP timeout in seconds (min 1, max 3600)
PIP_CVE_GATE_MAX_DEPTH	5	Max transitive dependency depth (min 1, max 50)
PIP_CVE_GATE_PIP_BIN	pip	Path to real pip binary
PIP_CVE_GATE_PIP_TIMEOUT	(unset)	Optional pip subprocess timeout in seconds; unset = no timeout
GITHUB_TOKEN	(unset)	Raises OSSF feed rate limit from 60 req/h to 5000 req/h

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Cross-platform support

CI runs the full happy + fail-closed + arg-parse fix smoke loop on each release inside fresh containers for:

Distro	Install path
Ubuntu (latest)	apt-get install python3 python3-pip
Debian (stable-slim)	apt-get install python3 python3-pip
AlmaLinux 9	dnf install python3 python3-pip
RHEL UBI 9	dnf install python3 python3-pip
macOS (Homebrew tap)	system python3 + Homebrew formula

Tested on Python 3.9 – 3.12. Runtime dependencies: requests, packaging (both standard).

If you hit a distro-specific issue, open a PR with a fresh entry in scripts/ci-cross-distro.sh — the smoke loop is the source of truth.

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Part of the safe-install fleet

pip-cve-gate is part of a pre-install CVE gate fleet for different package ecosystems:

Ecosystem	Tool
Homebrew	homebrew-safe-upgrade
Composer (PHP)	composer-cve-gate
pip (Python)	pip-cve-gate ← you are here

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Contributing

Bugs / feature requests: open an issue or PR. Security issues: see SECURITY.md.

Local development:

git clone https://github.com/sharkyger/pip-cve-gate
cd pip-cve-gate
python -m venv .venv && source .venv/bin/activate
pip install -e ".[dev]"
pre-commit install
pytest -v
ruff check src/ tests/

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License

MIT — see LICENSE.