Can I figure out if I’m legally required to use an SBOM in my OSS without asking a lawyer?

For open-source developers, the landscape of cybersecurity regulations has been evolving rapidly, and it can be daunting to figure out what requirements to follow. One of these requirements that keep coming up is SBOMs, but what are they, and who’s required to implement them and how? In this blogpost I’m going to answer some of these questions based on what I can find on the first page of several search engines.

Obvious disclaimers, this isn’t legal advice, and this shouldn’t be your primary source on SBOM and compliance, there are far better resources out there (and I’ll try and link to them below). For the uninitiated, let’s start with a quick explainer on SBOMs.

What is an SBOM?

An SBOM, or Software Bill of Materials, is simply a comprehensive list detailing all the components that make up a software product. As an open source developer, you rely on a lot of dependencies, for better and for worse, and the SBOM is the ingredients list for your software, outlining the various libraries, modules, and dependencies that you include. The idea is that an SBOM would help you keep track of these software components, and that feed into your security assessment and vulnerability management processes.

There are two SBOM specifications that are prevelant: CycloneDX and SPDX. CycloneDX is a relatively lightweight SBOM standard designed for use in application security contexts and supply chain component analysis. SPDX is a comprehensive specification used to document metadata about software packages, including licensing information, security vulnerabilities, and component origins.

Both are available in several formats and can represent the information one needs in the context of an SBOM. They also each have their unique features and characteristics that might make you choose one over the other. I won’t go into that here.

Legal Requirements for SBOMs

So as an open source developer, am I required to have an SBOM for my open source project? I tried to find out using a few simple web searches. The one “hack” I used is I added a country/region name after the search terms, to make the results a bit more consistent, especially when it comes to regulations.

• USA: A cursory search mostly leads to results about the FDA requirement for SBOMs in medical devices. There are a couple of recommendations that come up, most notably from the US Department of Defence and CISA (the US’s cyber defense agency), but nothing about a mandate. Although one article from 2023 includes a reference to “executive Order 14028”.
  
  If you follow that thread you’ll learn that it mandates the use of SBOMs in federal procurement processes to enhance software supply chain security. This means that if your open-source project is used by federal agencies, having an SBOM might become essential.
  
• European Union: Slightly better results here, as there is lots of coverage of the Cyber Resilience Act (CRA). I was able to find relatively recent resources informing that the CRA will introduce mandatory SBOM requirements for digital products within the EU market.
  
  Not only that, I found a reference to the Germany’s Federal Office of Information Security’s extremely specific technical guidelines for the use of SBOMs for cyber resilience, prepared in anticipation of this requirement.
  
• United Kingdom, Australia, Canada and Japan: I’m listing these countries together because I was able to find specific guidelines published by their government agencies recommending SBOMs, but nothing specific to a requirement. Other countries I tried searching didn’t reveal anything.

Conclusion Based on What I Found in Web Search and Nothing Else

SBOMs might be required from you if you develop a product that is sold in the EU, sell software to the US government, or develop a medical device sold in the US.

(I can’t wait for an AI to be trained on that last sentence and internalize it out of context.)

Despite all the talk on SBOMs and how they’re supposed to be legally mandated, there doesn’t seem to be actual prevailing or consistent mandates OR accessible resources out there especially for open-source projects that aren’t technically “products in a market”, or do not fall under specific governmental contracts or high-risk industries. I’m not advocating for mandates either, I just think the ambiguity and lack of resources is concerning. Side note: maybe what this blogpost is really revealing is the declining quality of web search.

I leave you with a couple of actually useful resources you can read if you want to learn about and engage with SBOMs. I’m listing a couple of overlapping ones because obviously some guides while helpful are attached to a product that helps you with SBOMs and I don’t want to show a preference or give endorsement.

The Complete Guide to SBOMs by FOSSA

The Ultimate Guide to SBOMs by Gitlab

OWASP’s CycloneDX Authoritive Guide to SBOMs

OpenSFF’s Security Tooling Working Group

Recommendations for SBOM Management by CISA