Software supply chain attacks exploit the gap between source code and deployed artifact. The SLSA framework (Supply-chain Levels for Software Artifacts) defines concrete requirements for closing that gap. It is not a tool you install – it is a set of verifiable properties your build process must satisfy.
SLSA defines four levels of increasing assurance:
Level 0: No guarantees. Most pipelines start here.
February 22, 2026
Your container image contains hundreds of dependencies you did not write. A compromised base image or malicious package runs with your application’s full permissions. Supply chain attacks target the build process because it is often less guarded than runtime.
The goal is to answer three questions for every artifact: what is in it (SBOM), who built it (signing), and how was it built (provenance).
A Software Bill of Materials lists every dependency in an artifact. Two tools dominate.