The PyPI Blog

PyPI has completed its second audit

In 2023 PyPI completed its first security audit, and I am proud to announce that we have now completed our second external security audit.

This work was funded by the Sovereign Tech Agency, a supporter of Open Source security-related improvements, partnering with Trail of Bits to perform the audit. Thanks to ongoing support from Alpha-Omega, my role at the PSF enabled me to focus on rapid remediation of the findings.

This time around, there's no three-part series, as the scope was narrower, focused only on PyPI's codebase and behaviors. Read on for a summary of issues identified, their resolutions, and more details about the audit process.

Incident Report: LiteLLM/Telnyx supply-chain attacks, with guidance

This post will drill deeper into two recent supply chain exploits, targeting users of popular PyPI packages - litellm & telnyx. We also provide Python developers and maintainers with guidance on what they can do to prepare and protect themselves from future incidents.

Dispatch from PyPI Land: A Year (and a Half!) as the Inaugural PyPI Support Specialist

Hello there! I am Maria, the inaugural PyPI Support Specialist. I go by "Thespi-Brain" on GitHub. I wanted to provide a dispatch of how this past year (and a half!) has been regarding my role and PyPI. PyPI has now reached over a million users and has over 700,000 projects. It is, without a doubt, a critical part of the Python ecosystem. As the inaugural PyPI Support Specialist, there were numerous challenges that needed to be tackled regarding PyPI support, such as the ever growing backlog of account recovery and PEP 541 issues.

PyPI in 2025: A Year in Review

As 2025 comes to a close, it's time to look back at another busy year for the Python Package Index. This year, we've focused on delivering critical security enhancements, rolling out powerful new features for organizations, improving the overall user experience for the millions of developers who rely on PyPI every day, and responding to a number of security incidents with transparency.

PyPI and Shai-Hulud: Staying Secure Amid Emerging Threats

An attack on the npm ecosystem continues to evolve, exploiting compromised accounts to publish malicious packages. This campaign, dubbed Shai-Hulud, has targeted large volumes of packages in the JavaScript ecosystem, exfiltrating credentials to further propagate itself.

PyPI has not been exploited, however some PyPI credentials were found exposed in compromised repositories. We've revoked these tokens as a precaution, there's no evidence they have been used maliciously. This post raises awareness about the attack and encourages proactive steps to secure your accounts, especially if you're using build platforms to publish packages to PyPI.

New Login Verification for TOTP-based Logins

We've implemented a new security feature designed to protect PyPI users from phishing attacks: email verification for TOTP-based logins from new devices.

Trusted Publishing is popular, now for GitLab Self-Managed and Organizations

Trusted Publishing has proven popular since its launch in 2023.

Recap: Trusted Publishing enables software build platforms to publish packages to PyPI on your behalf, eliminating the need to manage long-lived authentication tokens. After a one-time setup where you delegate publishing authority to your platform, it automatically obtains short-lived, scoped tokens for each build—no manual token management required.

Read the Security Model for a deeper understanding of how Trusted Publishing works.

Phishing attacks with new domains likely to continue

Unfortunately the string of phishing attacks using domain-confusion and legitimate-looking emails continues. This is the same attack PyPI saw a few months ago and targeting many other open source repositories but with a different domain name. Judging from this, we believe this type of campaign will continue with new domains in the future.

Token Exfiltration Campaign via GitHub Actions Workflows

Summary

I recently responded to an attack campaign where malicious actors injected code into GitHub Actions workflows attempting to steal PyPI publishing tokens. PyPI was not compromised, and no PyPI packages were published by the attackers.

Attackers targeted a wide variety of repositories, many of which had PyPI tokens stored as GitHub secrets, modifying their workflows to send those tokens to external servers. While the attackers successfully exfiltrated some tokens, they do not appear to have used them on PyPI.

I've invalidated all affected tokens and notified the impacted project maintainers. If you're one of them, I have emailed you from security@pypi.org.

Preventing Domain Resurrection Attacks

Summary

PyPI now checks for expired domains to prevent domain resurrection attacks, a type of supply-chain attack where someone buys an expired domain and uses it to take over PyPI accounts through password resets.

These changes improve PyPI's overall account security posture, making it harder for attackers to exploit expired domain names to gain unauthorized access to accounts.