SBOM is an inventory of a software system that allows tracking of each component and all information associated with it. But building and maintaining an SBOM is more complicated than just creating a list.
This article breaks down what an SBOM is, why it’s important, and how to use it for ensuring software system security.
Contents:
What is an SBOM?
A software bill of materials (SBOM) is a machine-readable inventory of all components, libraries, and modules present in a software product. This list helps organizations keep track of their software elements, their versions, and dependencies.
A well-made SBOM allows them to quickly identify vulnerabilities and mitigate security risks in complex supply chains.
Why is SBOM important?
Most modern software products contain open-source dependencies that pose real security risks. Bad actors know it — and they regularly attack supply chains to break the defenses. SolarWinds, Log4j, and XZ Utils are just a few high-profile examples.
Regulators have reacted too: Executive Order 14028, FDA requirements, and the EU Cyber Resilience Act now mandate SBOM adoption. With the average supply chain breach costing $4.91 million globally, keeping track of software inventory is critical.
An SBOM acts as a map of your software, helping you identify security risks, maintain compliance, and respond to vulnerabilities faster.
Without one, an organization is exposed to:
- Security breaches that lead to data compromise, revenue loss, and reputation damage
- Compliance failures resulting in fines or blacklisting
- Inability to react to incidents quickly, thus harming business trust
- Merger and acquisitions complications from inherited vulnerabilities or the inability to prove the security of a product to business partners
For software vendors, SBOMs are also an important trust factor, as enterprise buyers increasingly choose products that come with transparent, documented security practices.
What does an SBOM contain?
A complete SBOM gives you a structured, machine-readable inventory of everything in your software. The National Telecommunications and Information Administration (NTIA) minimum elements — refined by CISA’s 2024 framework — define what that inventory must include:
| Attribute | Contents |
|---|---|
| Component name & supplier | What the component is and who made it (e.g., log4j by Apache Software Foundation) |
| Version | Exact version in use (e.g., log4j 2.14.1), enabling precise vulnerability tracking |
| Unique identifiers | CPE, SWID tags, or Package URLs (PURL) for unambiguous component identification |
| Cryptographic hash | A unique fingerprint verifying the component’s integrity |
| License & copyright | Legal terms and rights associated with each component (e.g., MIT, Apache 2.0) |
| SBOM metadata | Author, timestamp, and the primary component being documented |
| Dependencies and their relationships | How components rely on one another |
Note: there are different types of dependencies, and all of them have to be documented. Types include direct/indirect dependencies and dynamic/runtime dependencies.
Direct dependencies are components your software explicitly includes, while transitive dependencies are pulled in indirectly by those components. Both need to be documented, as transitive dependencies are often where vulnerabilities hide.
Dynamic dependencies are loaded at runtime rather than declared at build time, while runtime dependencies are components the software requires to execute but doesn’t package itself — such as system libraries or external services. Both are easy to miss with standard scanning tools.
The attributes mentioned above are structured using open formats.
SBOM formats
SBOMs use standardized formats to ensure machine-readability and compatibility with security tools. CISA recognizes three formats, each serving different primary use cases:
| Format | Maintained by | Best for | File types |
|---|---|---|---|
| SPDX | Linux Foundation | Open-source license compliance | JSON, RDF, XML, YAML, tag-value |
| CycloneDX | OWASP | Security and vulnerability management | JSON, XML |
| SWID Tags | ISO/NIST | Software asset identification and inventory | XML |
SPDX was built around open-source compliance, providing a common exchange format for license and component information across the software supply chain.
CycloneDX takes a security-first approach, focusing on vulnerability identification, outdated component analysis, and supply chain risk. It integrates natively with tools like OWASP Dependency-Track, an open-source platform for component analysis.
SWID Tags supports software asset tracking, lifecycle management, and patch inventory in enterprise environments. Note that as of CISA’s 2024 guidance, SWID is no longer listed as a primary SBOM format but remains valid as a unique identifier within SBOMs.
For most teams, the choice comes down to priorities: CycloneDX is best for security and vulnerability management, while SPDX works well for open-source licenses.
SBOM lifecycle
An SBOM isn’t a one-time document. It must be constantly developed and updated throughout the development lifecycle. Its stages include:
- Generation. During the build process, automated scanning tools like Syft, CycloneDX CLI, or SPDX tools analyze source code and container images to inventory all components, capturing both direct and transitive dependencies in a standardized format.
- Integration. SBOMs are generated directly within CI/CD pipelines and tied to release artifacts, ensuring every software version is released with a corresponding, accurate inventory.
- Version control. SBOM changes are tracked alongside code, maintaining a historical record of how software composition evolves across releases and making it easier to pinpoint when a vulnerable component was introduced.
- Consumption. Security teams cross-reference SBOMs against vulnerability databases like the National Vulnerability Database (NVD) and Open Source Vulnerabilities (OSV) to identify affected components, assess risk, and prioritize remediation measures.
Manually updated SBOMs quickly become unreliable and inconsistent, especially in large systems. The solution to this problem is automation.
When embedded into the development pipeline from the start, an SBOM becomes a living document that reflects software’s actual state at any given point in time.
SBOM use cases for cybersecurity
An SBOM delivers the most value when integrated with security tools and systems that can act on its inventory — detecting vulnerabilities early, triggering updates, and automating compliance audits.
Vulnerability management
By cross-referencing an SBOM against CVE databases, security teams can instantly identify which components are affected by a newly disclosed vulnerability. Organizations with regularly updated and detailed SBOMs can locate affected systems in hours instead of spending weeks manually auditing their software.
License compliance
SBOMs document the license type of every component, making it straightforward to identify obligations tied to GPL, LGPL, Apache 2.0, and other licenses before they become legal liabilities.
Supply chain security
SBOMs provide verifiable documentation of every third-party and open-source component in your software, reducing the risk of unknowingly shipping compromised or tampered dependencies.
Regulatory compliance
Whether you’re subject to FDA requirements for medical devices, the EU Cyber Resilience Act, or NTIA/CISA guidelines, SBOMs serve as auditable proof that your software meets the required transparency standards.
M&A due diligence
During acquisitions, SBOMs give buyers a clear picture of the software risk they’re inheriting. This includes hidden vulnerabilities, outdated dependencies, or license conflicts that could affect the deal’s value.
SBOMs and regulatory compliance
SBOMs are becoming less of an option and more of a requirement across countries and industries.
United States
The US has been driving SBOM mandates since Executive Order 14028 (2021), which required SBOMs for all federal software procurement.
This was followed by NTIA’s minimum elements framework and CISA’s expanded 2024 guidance that introduced a maturity model for broader implementation.
The FDA now requires SBOMs for medical device software, and the Cyber Trust Mark program is incorporating SBOM transparency into its IoT security labeling initiative.
European Union
The EU Cyber Resilience Act (CRA) entered into force in December 2024 and will be fully enforced by December 2027. It requires SBOMs for all products with digital elements sold in the EU market, making it one of the broadest SBOM mandates globally. Organizations selling software or connected products in the EU should begin aligning with CRA requirements now.
Financial services
The financial sector increasingly recognizes that supply chain visibility is a core security practice. PCI DSS v4.0 introduced software inventory management requirements for organizations handling payment data.
Across all these regulations and frameworks, SBOMs serve the same core function: providing verifiable, auditable proof of what’s inside your software. The specific requirements differ by sector and region, but overall, regulators expect organizations to know their software components and be able to demonstrate that knowledge to customers and partners.
SBOM challenges
SBOMs are a powerful security tool, but implementation comes with real difficulties that organizations should plan for.
Tooling fragmentation
Different SBOM generators produce inconsistent outputs, even when targeting the same format. This makes it harder to compare or merge SBOMs across teams and vendors.
Transitive dependency completeness
Direct dependencies are relatively easy to capture, but indirect dependencies pulled in by those components are harder to track reliably. Incomplete transitive coverage is one of the most common gaps in real-world SBOMs.
Dynamic and runtime dependencies
Build-time SBOMs don’t capture components loaded at runtime or called from external services, leaving a portion of the actual attack surface undocumented.
Keeping SBOMs current
An outdated SBOM can be more dangerous than none at all, as it creates false confidence. Without CI/CD integration, SBOMs quickly fall out of sync with the actual software. This means that newly introduced or updated components with known vulnerabilities may go undetected.
Maintaining redacted SBOMs
In proprietary software scenarios, vendors may need to share SBOMs externally while protecting sensitive implementation details, requiring carefully maintained internal and redacted external versions.
How Apriorit supports SBOM implementation
With over 350 security projects completed, Apriorit brings cybersecurity-first engineering to every stage of SBOM implementation. Our teams are experienced in Secure SDLC practices, embedded and firmware SBOM generation, and compliance-aware development aligned with NTIA, CISA, and EU Cyber Resilience Act requirements.
Whether you’re introducing SBOMs for the first time or strengthening an existing process, our cybersecurity team can help you build a practical, maintainable SBOM document.
We do the following:
- SBOM generation. We combine automated, embedded-specific tools with manual source code reviews to ensure no component is overlooked.
- CI/CD and version control integration. Our engineers embed SBOM generation directly into a pipeline so the inventory stays current with every firmware change.
- Security testing. We validate your SBOM against known vulnerability databases, assess your attack surface, and identify weaknesses across both direct and transitive dependencies.
- Vulnerability prioritization and remediation. We identify and secure the most critical components first, so high-priority risks are addressed even under time constraints.
- Regulatory compliance. Our specialists ensure each SBOM meets industry-specific standards, whether that’s FDA requirements for medical devices, NHTSA for automotive, or other sector regulations.
Get maximum insight into your software
Lean on the leading cybersecurity experts to build you a reliable SBOM document that lives and evolves with your system. Let’s discuss your SBOM strategy today.
