Policy engine
Rules by package name, version range, age, source, license and custom criteria. Block or log-only, with time-limited exceptions. Re-evaluated on every request.
The next generation Dependency Firewall is launching soon. See what’s new
PyPI Dependency Firewall
PyPI is consistently one of the most targeted package registries. Typosquatting campaigns, malicious versions of legitimate packages, and environment-variable-stealing payloads have hit thousands of Python projects. The PyPI Dependency Firewall intercepts every pip install before it reaches your developers, CI/CD runners, and AI agent environments.
Bytesafe Dependency Firewall sits in front of your existing repository, protecting developers, CI/CD pipelines and AI agents.
EU-based company · Software supply chain security since 2018.
bytesafe.dev / Firewall
47
Blocked today
1,284
Requests today
12
Active rules
Package
Rule
Status
malicious-pkg@2.1.0
Malware scan
BLOCKED
lodash@4.17.20
CVSS ≥ 7.0
BLOCKED
react@19.1.1
Allowlist
APPROVED
new-release@0.0.1
Age < 7 days
DELAYED
axios@1.7.9
Allowlist
APPROVED
Blocked
malicious-pkg@2.1.0
By Exception
lodash@4.17.21
Delayed
new-release@0.0.1
Approved
react@19.1.1
Supply chain attacks on PyPI
A selection of documented supply chain attacks on PyPI. The PyPI ecosystem has been targeted by malicious packages, account takeovers, and dependency confusion attacks.
PyPI malware campaigns2026
Researchers document coordinated campaigns uploading hundreds of malicious PyPI packages in waves. Many impersonate cloud SDKs, test frameworks, and data science libraries commonly used in CI/CD and ML pipelines.
Bulk malware uploadultralytics2024
The ultralytics PyPI package (a popular computer vision library with millions of downloads) was compromised via a malicious GitHub Actions workflow. The attacker published versions with a cryptomining payload embedded.
Compromised packagerequests-darwin-lite2024
A package impersonating the requests library targeted macOS users specifically. It downloaded and executed a Mach-O binary. The package name was close enough to requests to fool automated dependency scanners.
Targeted attackctx2022
An attacker published a malicious version of the ctx package, which had been abandoned for years. The new version exfiltrated all environment variables to an external server. Any project using ctx in a CI/CD pipeline leaked secrets.
Account takeoverDependency confusion2021+
pip does not have native namespace isolation. Attackers register public packages with the same name as internal ones. Bytesafe Dependency Firewall can enforce that internal package names always resolve to your private index.
Namespace attackcolourama2018
A package named colourama (one letter from colorama, one of the most downloaded PyPI packages) contained a cryptocurrency clipboard hijacker. A single typo in requirements.txt installed malware silently.
TyposquattingDependency Firewall does not prevent all attacks, but blocks packages that match known malware signatures, fail provenance checks, or violate your policies.
Intercepts every PyPI package request before it reaches you.
Every package install is a potential entry point. Traditional SCA tools find problems after packages are already in your environment. Dependency Firewall intercepts every PyPI request before it reaches your developers, CI/CD pipelines or AI agents.
You define the rules: block packages with known CVEs, block known malicious packages, or delay newly published versions for a configurable period to give the ecosystem community time to surface zero-day threats.
Works in front of enterprise repository platforms and any PyPI registry. No agent installs. No workflow changes.
Public PyPI registry
Vulnerable and malicious versions included
Risky packages
Dependency Firewall
Policy engineVetted packages only
Developers and CI/CD
Internal environment
Dependency Firewall capabilities
Policy controls, malware blocking, package delay, provenance checks, publish scanning, and full audit visibility across every PyPI request.
Vulnerability blocking
Block packages with known CVEs before install. Filter by CVSS and EPSS severity per registry or team. New advisories take effect immediately.
Malware scanning
Detect malicious payloads, suspicious install hooks and obfuscated code before execution. Quarantined packages are logged and never silently dropped.
Provenance verification
Verify packages were built by expected publishers using Sigstore and SLSA attestations. Detect pipeline swaps and version downgrades early.
Dependency confusion
Block namespace attacks where public packages impersonate your internal ones. Configurable upstream priority rules ensure private packages always win.
Zero-day safety delay
Hold newly published versions for a configurable window (7 or 14 days) before they reach developers or pipelines. Gives the ecosystem time to surface threats.
Package observations
Every package is fingerprinted: first-seen date, download frequency, requester, version age. Know exactly what passed through and when.
Audit logging
Every block, allow and exception is recorded and exportable to your SIEM. Built to make security teams and auditors happy out of the box.
Publish scanning
Packages are scanned for malware, secrets, and sensitive data before they are published to an upstream registry.
Add a security layer to PyPI
Route PyPI package traffic through Dependency Firewall, define policies for what's allowed and let the firewall block the rest. Developers and pipelines keep their existing package manager commands.
01
Route PyPI requests through Dependency Firewall
Point your PyPI configuration at Dependency Firewall. Every install request passes through the firewall before reaching the registry or your environment.
02
Define your security policies
Set vulnerability thresholds, enable malware scanning, configure safety delays for new versions and write allowlist or blocklist rules. Create multiple firewalls with individual rules for different teams or projects.
03
Bad packages are blocked. Safe ones flow through.
Every request is evaluated in real time. Blocked packages are logged with the policy that triggered them. Approved packages are served transparently.
Configure pip to install through Dependency Firewall
Set your pip index URL to the Bytesafe Dependency Firewall endpoint. pip, Poetry, uv and Pipenv all support custom index URLs. Existing requirements files and pyproject.toml dependencies continue to work without changes.
Works with the repositories you already use
JFrog Artifactory
Sonatype Nexus
GitLab
GitHub Packages
Azure Artifacts
AWS CodeArtifact
Firewall rules
Each rule targets an ecosystem and applies a condition: vulnerability severity, package age, license type or name pattern. Rules either block or log. Stack multiple rules per firewall. Changes take effect immediately.
Security teams can start with broad guardrails, then narrow policies by upstream, package, version range, internal status, maximum age, CVSS score and EPSS score.
Live firewall logs
Every blocked package is logged: package name, version, status, ecosystem, which firewall evaluated it, which rule triggered and who requested it. Filter by firewall or user.
The log view gives developers a fast answer when an install fails and gives AppSec a complete audit trail for policy enforcement.
Package details and scorecards
Open a package to review advisories, licenses, project metadata, OpenSSF Scorecard checks, dependency counts and source links before deciding whether to block, allow or investigate further.
The package page brings runtime firewall context together with upstream project health. Security teams can compare CVEs, maintainer signals, and repository hygiene from the same screen.
Sits in front of what you already run
Other enterprise dependency firewalls are often bundled into repository platforms. Dependency Firewall is an independent firewall that works with any registry and is built in the EU.
| Criterion | Dependency Firewall | Other enterprise firewalls |
|---|---|---|
| Works with your existing repository | Yes, as a proxy in front of it | Bundled into their platform most often |
| Deploys in minutes | Yes | Usually weeks of platform work most often |
| Predictable pricing | Flat, no usage-based fees | Usage-based or opaque most often |
| EU data sovereignty | Yes | No, US-based most often |
PyPI Dependency Firewall: frequently asked questions
Common questions from security and engineering teams.
How do I configure pip to use Bytesafe Dependency Firewall?
Set the index-url in your pip.conf (or pip.ini on Windows) to your Bytesafe Dependency Firewall endpoint. For CI/CD, set the PIP_INDEX_URL environment variable. See docs.bytesafe.dev for the full configuration reference.
Does it work with Poetry, uv and Pipenv?
Yes. Poetry supports custom sources via [[tool.poetry.source]] in pyproject.toml. uv supports index configuration via uv.toml or environment variables. Pipenv supports PIPENV_PYPI_MIRROR. All point to the same Bytesafe Dependency Firewall endpoint.
Can I protect AI agent environments and model training pipelines?
Yes. AI and ML pipelines frequently run pip install in containers and serverless environments. Pointing those environments at Bytesafe Dependency Firewall ensures the same security policies apply to automated installs as to developer workstations.
Does it work with private Python packages on a private PyPI server?
Yes. Bytesafe Dependency Firewall can proxy multiple index sources. Internal packages resolve from your private PyPI server, and public packages resolve from PyPI. Dependency confusion attacks that target internal package names are blocked.
Can different projects have different policies?
Yes. You can create separate firewalls per project. They are lightweight and easy to clone. You can also differentiate by the user or token used for the session. Firewall configurations are small JSON files that can be managed in Git.
Can packages be delayed before they reach developers?
Yes. Dependency Firewall can hold newly published package versions for a configurable window (7 or 14 days) before they reach developers or pipelines. Centralizing delay rules means the protection applies automatically across all teams and pipelines without each project configuring it separately.
What happens if a package passes through but malware is found later?
The firewall tracks all packages via observations: first-seen date, last-seen date, and which firewalls they passed through. When new malware data surfaces, you can see exactly which projects downloaded the affected package and when.
Can firewall rules be automated?
Yes. All configuration is available via API. Configurations can be version-controlled in Git and deployed through your existing automation. All changes are tracked with full rollback support.
Does Dependency Firewall work with enterprise repository platforms?
Yes. Dependency Firewall speaks the same protocols as your package managers, so it is fully transparent to enterprise repository platforms and package registries, including JFrog Artifactory, Sonatype Nexus, GitLab, GitHub Packages and Azure Artifacts.
How is licensing structured?
Two plans: Cloud for SaaS and Enterprise for custom deployment, Managed Cloud or On-Premise. Both include unlimited users, package requests and bandwidth with no usage-based fees. See pricing for plan details and add-ons.
Watch it block PyPI threats
Book a 30-minute session and we'll show you how Dependency Firewall fits into your existing setup. Your registries stay unchanged.