Supply chain attacks exploit trust in package managers and CI/CD. These updates disrupt the attack lifecycle—from initial account compromise and 'pwn requests' to credential exfiltration—by enforcing stricter defaults, read-only caches, and secretless publishing.
In the past year, there’s been a pattern of supply chain attacks that target weaknesses in package repositories and CI/CD systems to quickly spread malware to hundreds of open source projects. This malware seeks to exfiltrate credentials both to broadly spread the attack, as well as for later exploitation.
We’ve written a few times about our plans for hardening the supply chain: Our plan for a more secure npm supply chain in September 2025, Strengthening supply chain security: Preparing for the next malware campaign in December 2025, and What’s coming to our GitHub Actions 2026 security roadmap in March 2026. In this post, we’re updating you on changes we’ve implemented that directly disrupt some of the most common and impactful supply chain attack techniques.
Supply chain attacks chain together several weaknesses, and there is no single security capability that can stop them. Addressing them takes a holistic approach, prioritizing the mitigations that break the most impactful links in the attack chain. Our teams have been studying these attacks to deploy several improvements that disrupt them and limit their impact. This is possible thanks to collaboration with the security research and developer communities.
The attacks vary in how they spread across the software ecosystem. However, most of these attacks follow similar techniques to gain initial access to a project, escalate privileges, and distribute across users and software. Improvements made to npm and GitHub Actions in the past few months have been focused on cutting off specific, common techniques and providing ways for customers to identify and respond to these attacks.
Attacks start by compromising a single project, often by directly compromising a maintainer’s account or by targeting the project’s actions workflows.
actions/checkout to prevent the checkout of untrusted code from forks in commonly exploited triggers unless you explicitly opt-out (after reviewing your risk). This change and its backport to older versions cut off one of the most common vulnerable code patterns leading to code execution in GitHub Actions CI/CD workflows and initial project compromise.Once an attacker has access to a single package, they then focus on detecting and exfiltrating credentials to gain further access and use in later exploitation across ecosystems.
With the credentials harvested from the previous step, attackers attempt to use those credentials to distribute their malware and compromise more projects and maintainers as quickly as possible.
In parallel to hardening npm and GitHub Actions to disrupt and limit the impact of supply chain attacks, we have also been working on making features and tools available to users to identify and respond to supply chain incidents that have impacted their projects and accounts.
Making our products more secure by default is a priority across npm and GitHub and we are prioritizing this work to target and disrupt supply chain attacks across the open source ecosystem. We’re proud of the work we’ve shipped towards this goal over the past months. There’s more to come, but we wanted to provide an update on the progress we’ve made and make folks aware of the new capabilities available to them. Be sure to follow our changelog and blog posts as we continue to roll out improvements.
Open source software is an incredible public good that we all benefit from, and this is one of several ways GitHub is working to continue to support the security, sustainability, and continued success of open source communities and the enterprises that depend on them.
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