Understanding What Software Bill of Materials (SBOM) Is

Published: June 4, 2025

Written by: Lizzie Danielson


Software supply chains have grown so complex that “what’s inside?” is no longer a rhetorical question. It’s a critical security demand. With attacks on open source software and third-party dependencies on the rise, knowing exactly what powers your application can mean the difference between a swift patch and a catastrophic breach.

This post provides a detailed breakdown of the Software Bill of Materials (SBOM)—what it is, why it matters, how it works, and how it’s evolving in the age of cloud-native apps. You’ll also find a clear FAQ and actionable guidance for implementing SBOMs in your security workflows.

Why security depends on transparency

Picture your software supply chain as a warehouse. Every time an update rolls out or a new vendor gets involved, the inventory changes a bit. If you don’t know precisely what’s entering and leaving, you’re inviting security threats to go undetected.

Cybersecurity incidents—from Heartbleed to Log4Shell and SolarWinds—have shown us how a single hidden vulnerability in a third-party package can cascade across thousands of organizations. This persistent risk is what drives the need for an up-to-date SBOM.

The SBOM serves as your detailed inventory list. It catalogs every component, library, and dependency forming the backbone of your software environment. According to recent guidance from the US government, SBOMs are essential for any organization that wants to improve software supply chain security.


SBOM explained

SBOM is a comprehensive list of all the individual components of a software product, including dependencies and metadata like version numbers and licenses. Think of it as the nutritional label for your codebase.

Why build an SBOM?

  • Transparency: Reveals what’s in your code.

  • Risk management: Flags components sourced from outside vendors or open source, so you can spot vulnerabilities quickly.

  • Compliance: Helps demonstrate adherence to regulations or answer legal queries about software origins and licensing.

Organizations without SBOMs are building software in the dark. That’s not just risky; it’s negligent.


The growing need for SBOMs

Attacks targeting software supply chains are up. As threat actors automate their reconnaissance, untracked dependencies have become favored hiding spots for malware and exploits.

The 2021 US Executive Order on Improving the Nation’s Cybersecurity elevated SBOMs from “nice-to-have” to “must-have,” especially for vendors supplying critical infrastructure or federal agencies. See official guidance.


Formats and standards for SBOMs

Not all SBOMs are built the same. Standardized formats allow software producers and consumers to share and interpret SBOMs without confusion.

The three most prominent SBOM formats are:

  • SPDX (Software Package Data Exchange): Widely adopted in open source communities. Offers detailed component, license, and relationship tracking.

  • CycloneDX: Designed for application security contexts, especially apt for cloud and container environments.

  • SWID (Software Identification Tags): Used by asset management tools for tagging and tracking software across environments.

Each format is machine-readable, supports automated toolchains, and is regularly updated by industry consortia.


Cloud native complexity and SBOM

The cloud era has transformed software from monoliths to sprawling mosaics of microservices, each bundled into containers. While this shift fuels speed and innovation, it also multiplies dependencies.

How do cloud-native apps impact SBOMs?

  • Scale: A single Kubernetes cluster might run thousands of microservices, often pulling from massive container registries.

  • Ephemeral builds: Containers spin up and down automatically, sometimes leaving little audit trail.

  • Third-party proliferation: Base images often bundle their own dependencies, multiplying the potential for hidden vulnerabilities.

SBOMs for cloud-native applications provide vital visibility. They inventory every component in every microservice, helping teams scan for vulnerabilities or compliance violations before they reach production.


Benefits of implementing SBOMs

SBOM implementation is not just about ticking a regulatory box. It’s about real security gains. Here’s what you can expect:

  • Faster vulnerability response: When a new CVE drops, you can immediately identify if you’re affected and where. No frantic codebase searches required.

  • Streamlined compliance and audits: Auditors and regulators increasingly ask for proof that organizations know their software’s origins and licenses. An SBOM is your ready-made answer.

  • Improved collaboration: Developers, security teams, and legal teams can all speak the same language about software components, reducing bottlenecks and misunderstandings.

  • Cost savings: Early detection of vulnerabilities saves significant time and money compared to patching after incidents.


Challenges in adopting SBOMs

That said, SBOMs don’t implement themselves. Leaders should anticipate these possible obstacles:

  • Tool and workflow integration: Existing CI/CD pipelines may require custom modifications to automatically generate and validate SBOMs at every release.

  • Maintaining accuracy: Dynamic environments mean the SBOM must update constantly, or it risks becoming obsolete fast.

  • Balancing transparency and IP protection: Sharing SBOMs with customers or partners can raise intellectual property concerns; organizations must find a safe middle ground.

  • Industry coordination: Wide adoption across the entire supply chain is required for maximum efficacy, and not every vendor is on board yet.

Despite these obstacles, the cost of inaction is far higher. A stagnant security program leaves organizations exposed to increasingly sophisticated attacks breaching the software chain.


Software Bill of Materials FAQs

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Proactive next steps for security teams

Adopting SBOMs isn’t just another checkbox, it’s a fundamental protection measure for modern cybersecurity. If your organization isn’t generating and using SBOMs for every critical application, start today:

  • Evaluate your current software inventory and exposure.

  • Choose an SBOM format that fits your environment (most vulnerability management and DevOps tools now support SPDX or CycloneDX).

  • Integrate SBOM generation into your build pipelines.

  • Train your development and security teams on reading and using SBOMs for faster incident response.

For formal standards and additional resources, review theNTIA’s official SBOM documentation.

Staying ahead in cybersecurity means knowing what you’re running, not just hoping that “someone else” is keeping track.