The era of the Software Bill of Materials (SBOM) is here. Driven by regulatory pressure and a growing awareness of supply chain risks, organizations are diligently generating these detailed dependency lists. But this has created a new, overwhelming problem: a firehose of vulnerability alerts. Your scanner lights up with a critical CVE found in a transitive dependency—a dependency of one of your dependencies—and panic ensues. But is the sky really falling?
For developers and AppSec engineers, the challenge has shifted from *generating* SBOMs to *operationalizing* them. The key to cutting through the noise and focusing on what truly matters lies in a powerful, emerging standard: the Vulnerability Exploitability eXchange (VEX). This guide provides a practical workflow for using VEX to triage your SBOM alerts and focus your patching efforts on genuine threats.
### The Problem: Drowning in Transitive Dependency Alerts
You’ve done everything right. Your CI/CD pipeline automatically generates an SBOM for every build using a tool like Syft or Trivy. You then scan this SBOM against a vulnerability database, and the result is a sea of red. A critical remote code execution (RCE) vulnerability has been found in `lib-xyz`, a library you’ve never even heard of.
The problem is that your application directly uses `lib-abc`, which in turn uses `lib-xyz`. The crucial question isn’t whether a vulnerability exists, but whether your code *actually calls the vulnerable function* within that transitive dependency. If it doesn’t, you are not affected. Without this context, your development teams are forced to waste countless hours chasing down and patching vulnerabilities that pose zero actual risk to your application.
### Introducing VEX: The Contextual Filter
VEX is a security advisory format designed to solve this exact problem. A VEX document is an assertion from a software provider (or a security team) about the exploitability of a specific vulnerability within their product. In essence, it’s a machine-readable statement that says, “For CVE-2025-12345 in this version of our software, the status is…”
The possible VEX statuses include:
* **Not Affected:** The code is not vulnerable.
* **Affected:** The code is vulnerable and a patch is recommended.
* **Fixed:** The vulnerability has been patched in a specific version.
* **Under Investigation:** The potential impact is still being analyzed.
By creating and applying a VEX document to your SBOM scan results, you can provide the missing context, automatically filtering out the noise of unexploitable CVEs.
### A Comparative Review of Tools
Several open-source tools are leading the way in integrating SBOMs and VEX to create a more intelligent vulnerability management workflow.
1. **Grype:** A popular vulnerability scanner from Anchore, Grype can take an SBOM as input and enrich its findings. While its direct VEX integration is still evolving, it’s a powerful tool for the initial scan.
2. **Trivy:** Another widely used scanner from Aqua Security, Trivy also excels at generating SBOMs and scanning them for vulnerabilities. Like Grype, its ecosystem is rapidly incorporating VEX-like concepts.
3. **Dependency-Track:** This is where the workflow comes together. Dependency-Track is a dedicated platform for ingesting and analyzing SBOMs. It has robust support for importing vulnerability data and, crucially, for uploading and applying VEX documents to suppress false positives.
### Building an Automated Triage Workflow
Here is a practical, four-step workflow to move from a noisy SBOM to an actionable, prioritized list of real risks.
**Step 1: Generate the SBOM**
In your CI/CD pipeline, add a step to automatically generate an SBOM for your application artifact. For a container image, this is as simple as:
`syft my-app:latest -o cyclonedx-json > sbom.json`
**Step 2: Scan for Vulnerabilities and Ingest**
Scan the generated SBOM for vulnerabilities and upload both the SBOM and the scan results to Dependency-Track.
`grype sbom:./sbom.json -o cyclonedx-json > vulnerabilities.json`
*(Use Dependency-Track’s API to upload `sbom.json` and `vulnerabilities.json`)*
**Step 3: Analyze and Create a VEX Document**
Now, for the critical CVE your scan uncovered in `lib-xyz`, your security team or lead developers perform a quick analysis. They determine that your application’s use of `lib-abc` never invokes the vulnerable code path in `lib-xyz`. They can now create a simple VEX document asserting this. A VEX in CycloneDX format might look like this (simplified):
“`json
{
“bomFormat”: “CycloneDX”,
“specVersion”: “1.4”,
“serialNumber”: “urn:uuid:…”,
“version”: 1,
“vulnerabilities”: [
{
“id”: “CVE-2025-12345”,
“analysis”: {
“state”: “not_affected”,
“justification”: “code_not_reachable”,
“detail”: “Our application does not use the vulnerable function in the transitive dependency.”
}
}
]
}
“`
**Step 4: Apply VEX and Prioritize**
Upload this VEX document to Dependency-Track. The platform will automatically process this information, and the “critical” CVE will be suppressed from your list of open vulnerabilities. Your dashboard is now clear of this false positive.
By automating the first two steps and establishing a clear process for the third and fourth, you can create a powerful feedback loop. The result is an automated system that flags potential vulnerabilities, enriches them with exploitability data (like EPSS scores), and allows you to systematically eliminate false positives. This frees up your developers to focus on patching the vulnerabilities that represent a genuine, measurable risk to your organization.
In mid-2025, an SBOM is no longer enough. The true mark of a mature DevSecOps practice is the ability to operationalize that SBOM, using tools like VEX to transform a mountain of data into a prioritized, actionable, and ultimately, effective security strategy.
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