meta-vulnscout

meta-vulnscout is a Yocto meta-layer that uses VulnScout to scan a project, export its Software Bill of Materials (SBOM), and list the vulnerabilities affecting it.

Currently the supported formats are: CycloneDX, SPDX, Yocto JSON files, and OpenVEX.

Getting Started

Requirements

• docker command

• python3-packaging package

Installation

Clone the repository next to where you store your other layers (like sources or layers directory) and add it to your build/conf/bblayers.conf file:

git clone https://github.com/savoirfairelinux/meta-vulnscout.git

And in your bblayers.conf file add the line:

BBLAYERS += "/path/to/meta-vulnscout"

Configuration

The distro poky-vulnscout provided in this repo provides an example of a complete usage of meta-vulnscout features. For more control on the features enabled, please follow the following steps.

Enable VulnScout

To enable and configure VulnScout for all images, add the following lines to your local.conf or distro config:

# Required settings for VulnScout
require conf/distro/include/vulnscout-core.inc

This configuration enables VulnScout for all image recipes and should be sufficient for most users.

For more fine-grained control on which images have VulnScout enabled, do not use the previous require line but add to your local.conf or distro config:

# Inherit create-spdx to generate SBOMs
# May be required if not using poky distro
INHERIT += "create-spdx"

HOSTTOOLS_NONFATAL += "docker"

And then manually add inherit vulnscout in specific image recipes to enable VulnScout for them.

Enable CVE Checking

To enable a complete CVE scan of your project, it is recommended to use the sbom-cve-check tool included in Yocto. Add to your local.conf or distro config:

OE_FRAGMENTS += "core/yocto/sbom-cve-check"

Using VulnScout Web Interface

Configure and Serve Web Interface

The scan and analysis of vulnerabilities can be started with:

bitbake core-image-minimal -c vulnscout

VulnScout Docker container can also be started without rescanning for new CVEs with the following command:

bitbake core-image-minimal -c do_vulnscout_no_scan

Or you can do it manually with the command:

docker exec vulnscout /scan/src/entrypoint.sh --serve

Without a custom configuration, a web interface will be started at the address http://localhost:7275

After a normal build, you should see a new .vulnscout folder in ${TOPDIR}/.. (can be modified with variable VULNSCOUT_ROOT_DIR).

Projects and Variants

meta-vulnscout organises data into projects and variants.
A project typically maps to a product, and variants represent different builds or architectures as the machine, the image or even the distro (e.g. x86_64, aarch64).

By default the project name is default and can be changed through the variable VULNSCOUT_PROJECT in the local.conf file.

And the variant is set as <distro>_<machine>_<image> of your build (e.g. poky_qemux86-64_ccore-image-minimal). It can be changed through the variable VULNSCOUT_VARIANT in the local.conf file.

Using VulnScout With a CI

Launch CI Mode

It is possible to launch VulnScout in a non-interactive mode, also known as CI mode. This mode will scan for vulnerabilities and automatically generate reports, without user interaction. To execute it, use the command:

bitbake core-image-minimal -c vulnscout_ci

All the files generated by vulnscout will be placed by default here: <project_root>/.vulnscout/

Options

vulnscout in CI mode can be launched with a specific match condition using an environment variable.

First you need to export the environment variable BB_ENV_PASSTHROUGH_ADDITIONS+=" VULNSCOUT_MATCH_CONDITION"
For example, using the export command:

export BB_ENV_PASSTHROUGH_ADDITIONS+=" VULNSCOUT_MATCH_CONDITION"

Or every time you launch vulnscout in the CI mode:

BB_ENV_PASSTHROUGH_ADDITIONS+=" VULNSCOUT_MATCH_CONDITION" bitbake core-image-minimal -c vulnscout_ci

Now you can specify the match condition with the VULNSCOUT_MATCH_CONDITION variable every time you use vulnscout in CI mode:

VULNSCOUT_MATCH_CONDITION="cvss >= 9.0 and (pending == true or affected == true)" BB_ENV_PASSTHROUGH_ADDITIONS+=" VULNSCOUT_MATCH_CONDITION" bitbake core-image-minimal -c vulnscout_ci

With this command, vulnscout will list all the CVEs of the vulnerabilities with a CVSS score equal to or higher than 9.0.

It's possible to set more than one condition:

VULNSCOUT_MATCH_CONDITION="cvss >= 9.0 or (cvss >= 7.0 and epss >= 50%)" bitbake core-image-minimal -c vulnscout_ci

With this command, vulnscout will list all vulnerabilities critical (CVSS >= 9.0) or those with both a high CVSS and EPSS score.

NOTE
Setting up the match condition this way will override the "VULNSCOUT_MATCH_CONDITION"

WARNING
If you set the "VULNSCOUT_MATCH_CONDITION" with the export command in your shell, it will always use it until you set it to null

Generating Reports

meta-vulnscout is capable of generating built-in reports and even custom ones. The built-in reports are the following:

• all_assessments.adoc
• match_condition.adoc
• summary.adoc
• time_estimate.csv
• vulnerabilities.csv
• vulnerability_summary.txt

All Custom reports must be placed in the following folder .vulnscout/custom_templates Custome report should follow the template format of VulnScout.

NOTE
The custom_templates could be changed through the "VULNSCOUT_CUSTOM_TEMPLATES_DIR" variable in the local.conf file.

There are two ways to generate reports with meta-vulnscout

Generating Reports Without a Scan

Multiple reports can be created within one command without a scan.

You must specify the reports you wish to generate to the variable "VULNSCOUT_REPORT" in the local.conf file. By default it will generate the summary.adoc

Example:

VULNSCOUT_REPORT = "summary.adoc time_estimate.csv"

Then reports can be created without scan using the command:

bitbake core-image-minimal -c vulnscout_report

The reports are generated by default in the folder .vulnscout/<image_basename-machine_suffix>/

Generating Reports During CI Scan

When launching a CI scan you can specify one or multiple reports to be generated at the same time in the variable VULNSCOUT_REPORT_CI.

For example, there is a match_condition.adoc template embedded in VulnScout which is relevant for CI pipelines, and it can be used with:

VULNSCOUT_REPORT_CI = "match_condition.adoc"

Now, when using the command -c vulnscout_ci the reports will be automatically generated.

Exporting SBOM Files

meta-vulnscout can export the enriched project data as standard SBOM formats. Exported files are written to the outputs directory (default: .vulnscout/<image_basename-machine_suffix>/).

To export the SBOM files, you have to specify the files in the variable "VULNSCOUT_EXPORT" in the local.conf.

For now you can export three types of SBOM:

• cdx
• spdx
• openvex

Finally you just need to launch the command:

bitbake core-image-minimal -c vulnscout_export

Use Environment Variables in Templates

In VulnScout templates, you can use environment variables as stated in the documentation. These variables should be automatically detected if they are in a template in the custom_templates directory, and that the template is in use in VULNSCOUT_ENV_GENERATE_DOCUMENTS.

Accelerate NVD Database Download

For faster NVD database downloads during VulnScout setup, you can set an NVD key with the variable NVDCVE_API_KEY.

Yocto Documentation reference : https://docs.yoctoproject.org/ref-manual/variables.html#term-NVDCVE_API_KEY

You can generate a new NVD key at : https://nvd.nist.gov/developers/request-an-api-key

Using the Web Interface When Building in a Docker Container

The Yocto task vulnscout creates and starts a Docker container with a Web interface available.

Using a Docker container to build the project requires additional configuration to access the web interface.

Indeed, the web interface won't be mapped to the host if the Docker container used to build is not properly configured.

CQFD requires adding docker-cli to .cqfd/docker/Dockerfile and exporting the following variable:

export CQFD_EXTRA_RUN_ARGS="-v /run/docker.sock:/run/docker.sock"

For a permanent change, you can instead modify the .cqfdrc file with docker_run_args="-v /run/docker.sock:/run/docker.sock".

Now, you can build your image and use the vulnscout task with one of these commands:

If you use CQFD and KAS

cqfd kas shell -c "bitbake -c <your_Yocto_image> -c vulnscout"

Variables Glossary

meta-vulnscout can be configured through variables in the local.conf. Here is a recap of all the variable and their impact:

Variable	Purpose
VULNSCOUT_ROOT_DIR	Root directory of the ./vulnscout
VULNSCOUT_BASE_DIR	Base directory of the ./vulnscout configuration and output files
VULNSCOUT_DEPLOY_DIR	Directory of the ouput files (reports, exports, ...)
VULNSCOUT_CACHE_DIR	Directory of the cache used by vulnscout (database, docker config file)
VULNSCOUT_CUSTOM_TEMPLATES_DIR	Directory used to implement custom template to vulnscout
VULNSCOUT_CONFIG_FILE	Docker config file
VULNSCOUT_VARIANT	Name of the variant used in vulnscout
VULNSCOUT_PROJECT	Name of the project used in vulnscout
VULNSCOUT_EXPORT	SBOM files to generate with the command -c vulnscout_export ( the value has to bee spdx, openvex or cdx)
VULNSCOUT_REPORT	Reports to generate with the command -c vulnscout_report using templates.
VULNSCOUT_REPORT_CI	Reports generated automatically when during -c vulnscout_ci
VULNSCOUT_IMAGE_VERSION	Version of the container image to use. If the version set in the variable is not the same as the container image used, recreate the vulnscout container.
VULNSCOUT_IMAGE	Name of the container image to use for vulnscout container.
VULNSCOUT_ENV_VERBOSE_MODE	Enable or disable the verbose mode (false by default)
VULNSCOUT_ENV_FLASK_RUN_PORT	Port vulnscout used for the Web Interface (7275 by default)
VULNSCOUT_ENV_FLASK_RUN_HOST	IP used on the host for the Web Interface (0.0.0.0 by default)
VULNSCOUT_ENV_IGNORE_PARSING_ERRORS	Enable or disable to ignore parsing error found in the entry SBOM files. (false by default)
VULNSCOUT_MATCH_CONDITION	Match-condition to set by default to avoid precise it everytime during the command -c vulnscout_ci

License

Copyright (C) 2025-2026 Savoir-faire Linux, Inc.

meta-vulnscout is released under the Apache License 2.0.