Open-source Snyk Container alternatives: one tool per job, and what you give up

There is no single open-source Snyk Container. There is a tool for each of its jobs: Trivy or Grype for the image scan in CI, Renovate or Dependabot for base-image updates, Harbor for the registry, Trivy Operator, Kubescape or StackRadar Community Edition for the running cluster, and Dependency-Track or DefectDojo for the reports. Put together, they cover most of what you pay Snyk for, nothing leaves your network, and the bill is the time it takes to run them.

This post is for teams who like what Snyk Container does but have a problem with how it is sold or where it runs: pricing that follows developer headcount, images and SBOMs sent to a SaaS tenant, or a cluster view that needs an enterprise contract. It goes job by job, names the open-source tool for each, and says where Snyk is still better. For the general comparison of Snyk Container with commercial products, see Snyk Container alternatives; for the broader question of keeping vulnerability data in your own cluster, see self-hosted vulnerability management for Kubernetes.

Why teams go looking for an open-source alternative

Snyk Container is a good product, and most people who leave it say so. The reasons they give are about the model, not the scanner:

• Price follows people. The Free plan includes 100 container tests. The Team plan starts at $25 per month for up to ten developers, and Snyk counts contributing developers. A platform team scanning images on behalf of fifty engineers pays for the fifty.
• The cluster is an Enterprise feature. Importing workloads from a running Kubernetes cluster needs the Enterprise plan, which is quote-only. On Free and Team, Snyk sees what you scan in CLI, CI and registries, not what is running.
• Your data sits in Snyk's region. The EU and Australian regions are Enterprise-only too, so a European team on Team keeps its image inventory in the US. For some companies that ends the conversation.
• The scanner is closed. The Snyk CLI is Apache-2.0, but it is a client: matching happens against Snyk's curated database on Snyk's side, and the CLI repository has not taken outside contributions since July 2024.

None of these is a defect. They are how a SaaS developer platform is built and sold. If they are your constraints, the jobs below are the ones you need to cover yourself.

The four jobs, and who does each

Job 1: scanning images in the CLI and CI

This is the easiest job to replace. Trivy (Aqua Security) and Grype (Anchore) are both Apache-2.0, both scan an image from a registry or a local daemon, both read the common Linux distributions and language package managers, and both return a non-zero exit code when a finding crosses a threshold you set. Grype works with Syft, its sister project, so you can generate an SBOM once and match it again later without pulling the image.

# Trivy: fail the job on any critical finding
trivy image --exit-code 1 --severity CRITICAL registry.example.com/app:1.4.0

# Grype: the same gate, and the findings ordered with KEV entries first
grype registry.example.com/app:1.4.0 --fail-on critical
grype --sort-by kev nginx:1.25.5

The difference you will notice is the ranking. Snyk orders findings by its Risk Score, which combines CVSS, EPSS, exploit maturity and reachability. Grype has its own risk score built from EPSS and CISA KEV, and can sort KEV entries to the top. Trivy reports CVSS severity only, so with Trivy you join the EPSS and KEV feeds yourself or accept a longer list. Neither has Snyk's curated database: they match against public sources (the distributions' own trackers, GitHub advisories, OSV), which is more transparent but means you will sometimes see a finding Snyk had triaged away, and the other way round.

What you lose is the developer workflow around the scan. Snyk's IDE plugins, pull request checks and fix advice in the output have no single open-source equivalent. You can get close with a CI job that posts Trivy or Grype output as a pull request comment, but someone has to build and maintain that job.

Job 2: keeping base images current

Most container fixes do not come from changing code. They come from rebuilding on a newer base image. Snyk handles this with automated pull requests that bump the FROM line, and with recommendations for an alternative base image that has fewer known vulnerabilities.

The open-source half of that is Renovate or Dependabot. Pin the base image by digest, and either bot opens a pull request when the tag you follow gets a new build. Distributions rebuild tags like debian:bookworm-slim for months, so this alone removes a large share of findings. We walk through the setup in base-image vulnerabilities vs your own and patching CVEs in Kubernetes.

The half you lose is the recommendation. Renovate keeps you on the base you chose; it does not tell you that a slim, Alpine or distroless variant would carry a third of the findings. Teams that rely on that advice usually keep Snyk for this job alone, or replace it with a quarterly look at the base images they use most.

Job 3: monitoring what you ship and what runs

Snyk Container monitors images in a registry and, on Enterprise, workloads in a cluster. These are separate questions and the open-source answers are separate tools.

The registry: Harbor. If your images pass through a registry you run, Harbor (a CNCF graduated project) scans them with Trivy on push and on a schedule, keeps the results with each artefact, and can block pulls above a severity. It sees everything you pushed, including images that never ran, and nothing a pod pulled from somewhere else.

The cluster: Trivy Operator or Kubescape. Both run inside the cluster and scan the images your workloads actually use. Trivy Operator writes a report per workload as a Kubernetes resource and adds configuration and RBAC checks; reports are regenerated rather than kept, and on big clusters they put real load on etcd. Kubescape focuses on posture and adds a runtime signal that marks which vulnerable packages are actually loaded; its history, EPSS and KEV views live on ARMO's commercial platform.

The cluster, with history: StackRadar Community Edition. This is our project, so read this paragraph with that in mind. The scanner watches the pods in one cluster and builds one SBOM per running image digest. The server keeps every SBOM and finding with history, mirrors OSV.dev hourly and the EPSS and KEV feeds daily, and re-matches stored SBOMs when the mirror changes, so a new CVE shows up without a rescan. Each finding carries its namespace, workload and Helm release. It is one Helm install:

helm install stackradar \
  oci://ghcr.io/lockdep/helm-charts/stackradar \
  --namespace stackradar --create-namespace

Job 4: reporting across teams

Snyk's reporting works because everything is in one tenant: containers, open-source dependencies and code findings, grouped by organisation and project. Open source splits this too.

OWASP Dependency-Track keeps CycloneDX SBOMs per project and re-evaluates them as advisories change, with EPSS, policies and a portfolio view. It is the right reporting layer if your SBOMs come from CI and cover more than containers. It does not generate SBOMs, so the pipeline that feeds it is yours.

OWASP DefectDojo imports reports from well over a hundred scanners, Trivy and Grype among them, deduplicates them, and adds SLAs, risk acceptance and Jira tickets. It is the right layer if a security team wants one queue across containers, code scanning and pentests. It does not re-check old imports against new advisories.

Both are solid and both are real applications to operate, with a database, upgrades and a feed mirror or an importer to keep running.

What the switch costs you

The licence fee goes to zero. What replaces it:

• Glue. Snyk's jobs share one login, one database and one set of projects. Four open-source tools share nothing until you connect them: a CI job here, a Renovate config there, an SBOM upload, a dashboard nobody else can see without access.
• Operations. Harbor, Dependency-Track, DefectDojo and StackRadar CE each need a database you back up and upgrades you read the notes for. Trivy, Grype and the bots need almost nothing.
• Developer experience. The IDE plugin, the pull request annotations and the fix advice are the parts that have no direct replacement. If your developers fix vulnerabilities themselves because Snyk shows them where, losing that is the largest cost on this list.

What to pick

• You only used Snyk in CI: Grype or Trivy in the pipeline, Renovate for base images. This is a weekend of work and most teams do not miss Snyk afterwards.
• Your developers live in Snyk's IDE and PR checks: keep Snyk for them. Add an open-source tool only for what Snyk does not show you on your plan, which is usually the running cluster.
• You need to know what is running, and Enterprise is not an option: Trivy Operator or Kubescape for the current state and posture; StackRadar CE if you also want history, EPSS and KEV ordering, and new advisories matched against what already runs.
• You need reports across many teams and many scanners: Dependency-Track if your input is SBOMs, DefectDojo if it is scanner reports.

Snyk's value is that one product does all four jobs with a good developer experience. Leaving it makes sense when the price or the data location is the problem, and the jobs you actually use can be covered by one or two tools rather than all four.

Frequently asked questions