OpenSSF
Cross-industry initiative for open-source software security
The Open Source Security Foundation (OpenSSF) is a Linux Foundation initiative that brings together companies, individual maintainers, and researchers to improve the security of open-source software supply chains. It develops shared…
Definition
The Open Source Security Foundation (OpenSSF) is a Linux Foundation initiative that brings together companies, individual maintainers, and researchers to improve the security of open-source software supply chains. It develops shared tooling, best-practice guidance, and metrics such as automated scorecards for assessing project security posture, aiming to reduce the risk that vulnerabilities hidden in widely depended-upon open-source packages introduce into downstream commercial and internal software.
Overview
OpenSSF was formed in response to a growing recognition that modern software supply chains depend on enormous trees of open-source packages, many maintained by small volunteer teams without dedicated security resources, creating systemic risk that any single company or project cannot address alone. High-profile supply-chain incidents involving compromised or vulnerable open-source dependencies made clear that security improvements needed cross-industry coordination and shared tooling rather than each organization independently auditing the same upstream code. Mechanically, OpenSSF operates through working groups and hosted projects that each target a specific piece of the supply-chain security problem. The Scorecards project automatically evaluates open-source repositories against security-relevant signals like branch protection, dependency update automation, and fuzzing coverage, producing a numeric score maintainers and consumers can track over time. Sigstore provides free code-signing infrastructure so software artifacts can be cryptographically signed and verified without maintainers managing their own key infrastructure, and the foundation also publishes best-practices badges that projects can earn by meeting documented security criteria. Within the broader security landscape, OpenSSF differs from commercial application-security vendors in that its output is largely open tooling and guidance rather than a paid product, and it differs from a single project's own security team in that it coordinates practices across the entire open-source ecosystem rather than one codebase. It works closely with CNCF-hosted projects and standards bodies, since securing the software supply chain touches container images, build pipelines, and package registries maintained across many different foundations. In practice, organizations consume OpenSSF's work by running Scorecards against their dependencies to flag risky packages, adopting Sigstore to sign build artifacts, and referencing OpenSSF guidance when building internal supply-chain security policies or responding to regulatory requirements around software bill of materials disclosure. Maintainers use the best-practices badge and scorecard feedback as a checklist for hardening their own projects' security posture. The foundation's guidance and tooling improve visibility into supply-chain risk but cannot force upstream maintainers to adopt them, and a low scorecard result does not necessarily mean a project is actively vulnerable, only that certain protective practices are absent, so its outputs work best as one input alongside dedicated vulnerability scanning and manual review rather than a sole trust signal. Adoption across the open-source ecosystem also remains uneven, since many maintainers are volunteers with limited time to act on recommendations, which means large, well-funded organizations often end up doing more of the remediation work than the maintainers of the packages they depend on.
Key Concepts
- Coordinates cross-industry efforts to secure open-source software supply chains
- Scorecards project automates repository security posture scoring
- Sigstore provides free cryptographic signing infrastructure for software artifacts
- Best Practices badge lets projects demonstrate adherence to security criteria
- Operates under the neutral governance of the Linux Foundation
- Publishes guidance relevant to software bill of materials requirements
- Working groups target specific supply-chain risk areas