Containers redefine how organizations deploy and manage cloud-native applications, giving them the agility to run workloads anywhere with greater consistency and efficiency. But that same flexibility also expands your attack surface. Misconfigured images and outdated dependencies can expose critical systems to threats, and as deployment spreads across Kubernetes and hybrid clouds, controlling every component becomes more challenging.
Container security tools bring order to that complexity. They continuously scan images, monitor runtime activity, and enforce the guardrails that keep workloads safe and compliant. This article breaks down what these tools are, explores their key benefits, highlights some top options to consider, and explains how to choose the right fit for your environment.
What Are Container Security Tools?
Container security tools are purpose-built solutions that protect containerized applications—lightweight packages that bundle everything an application needs to run consistently—from image creation to runtime. At a basic level, these tools identify vulnerabilities and misconfigurations within container images and environments, but advanced platforms also manage access controls and enforce security policies.
Container scanners analyze image contents to uncover outdated dependencies and exposed secrets before deployment. They often integrate directly with container registries or CI/CD pipelines, so they can flag vulnerabilities as developers build images. One recent example of a vulnerability, CVE-2024-21626, exposed a flaw in the runC runtime that allowed attackers to escape a container and access the host file system through a file descriptor leak.
Other container security solutions focus on post-deployment protection, detecting anomalous behavior, and managing visibility across distributed workloads. Together, these capabilities create a stronger approach to container vulnerability management, reducing risk while maintaining the agility that makes containers so valuable.
What Are the Benefits of Container Security Tools?
As more organizations move workloads into containers, security risks follow close behind. Containers often share the same kernel as the host system, which means a single misconfiguration or vulnerable image can give attackers a direct path to infrastructure. Here’s how strong container security can address those risks.
Prevent Container Escapes and Zero-Day Exploits
Container security tools can’t eliminate every zero-day risk, but they make incidents far less likely. Image scanners catch known vulnerabilities before deployment, admission controllers block unsafe builds, and runtime agents detect and stop unusual activity that might signal a breakout attempt. When combined with timely patching and least-privilege access, these tools maintain strong isolation across workloads.
Protect the CI/CD Pipeline From Risky Images
By integrating container image scanning into CI/CD pipelines, security systems can catch outdated dependencies and risky configurations. They can also use automated policies to enforce baseline security standards across registries and orchestrators like Kubernetes.
Use AI to Prioritize Vulnerabilities Faster
Some newer platforms use AI to identify anomalies faster and prioritize vulnerabilities based on exploitability. For organizations under regulatory pressure, this continuous assurance supports compliance reporting with standards and frameworks like CIS Benchmarks and the Payment Card Industry Data Security Standard.
Real-Time Runtime Protection
Container security tools simplify what used to be reactive work, by monitoring runtime activity in real time and flagging privilege escalations or data exfiltration attempts before they spread. The result is faster remediation, fewer false positives, and a more resilient container ecosystem that scales without sacrificing control.
8 of the Best Container Security Tools
A strong mix of container scanning tools and runtime visibility allows DevOps and security teams to secure builds and manage compliance with less friction. The following tools stand out for their reliability in closing visibility gaps across the container lifecycle.
1. Anchore
Anchore brings policy-driven image assurance and software bill of materials (SBOM) management into the CI/CD pipeline. Teams can define fine-grained rules, scan images automatically, and gate releases based on compliance with internal or external standards. Plus, Anchore’s command-line and API options make it easy to embed scanning in existing workflows.
2. Clair
Clair performs static analysis of container images, checking them against multiple vulnerability databases. This is a lightweight tool that fits naturally into CI pipelines or registries to catch common vulnerabilities and exposures before deployment.
3. Falco
Falco monitors runtime activity at the kernel level and alerts teams to suspicious behavior using rule-based detection. This solution is widely used in Kubernetes environments to spot anomalies such as privilege escalations or network activity outside approved patterns.
4. Trivy
Trivy is a fast, open-source scanner that covers operating system packages, dependencies, infrastructure as code, and Docker images. It also generates SBOMs to strengthen supply chain security, and it integrates easily with Docker, Kubernetes, and common CI/CD systems.
5. Kubescape
Kubescape focuses on Kubernetes posture and compliance. It scans clusters and running workloads against benchmarks like the NSA and CISA Kubernetes Hardening Guide and MITRE ATT&CK mappings. The results highlight misconfigurations and vulnerabilities across images and cluster settings in one place, giving a clearer view of your overall Kubernetes security posture.
6. Cilium
Cilium secures and monitors network traffic between containers using eBPF, a Linux kernel technology that allows real-time visibility and control over system activity. This lets your team enforce identity-based network policies and limit lateral movement between workloads without adding heavy agents or proxies.
7. Calico Open Source
Calico Open Source provides scalable network policy enforcement for Kubernetes clusters. It supports microsegmentation, namespace isolation, and detailed policy control to prevent unauthorized traffic between workloads. It’s widely used for securing container-to-container communication in hybrid and multi-cloud setups.
8. Harbor
Harbor acts as a trusted container registry that embeds vulnerability scanning and role-based access control. It enforces security and compliance policies at the registry level, ensuring that only verified images make it into production.
How to Choose the Right Container Security Tool
Choosing the right solution requires understanding what your environment needs most. Some tools excel at scanning and policy enforcement, while others specialize in runtime detection or network control.
When evaluating your options, focus on features that provide:
- Strong coverage across the lifecycle: Look for tools that bake container image scanning into CI/CD and your registries, and that generate SBOMs for supply chain visibility. This combination catches outdated dependencies early and keeps unvetted images out of production.
- Runtime awareness: A good solution will give you syscall-level visibility—often powered by eBPF—so you can spot suspicious activity as it happens. The best tools combine anomaly detection with automated policy enforcement to shut down privilege abuse or data exfiltration attempts in real time.
- Built-in policy enforcement and automation: Favor tools that let you gate builds and deployment with admission controls and automatically open tickets or fixes when scans fail. Strong policy engines and pipeline integration reduce drift between what’s approved and what’s running.
- Network isolation: Your container security system should support microsegmentation and identity-based network rules to keep workloads separated. Isolating container traffic reduces lateral movement, so if an attacker compromises one workload, the impact stays contained and easier to respond to.
- Scale securely and stay audit-ready: Finally, your chosen tool should scale across clusters without heavy overhead and align with compliance benchmarks. Look for clear, actionable reporting that keeps your team prepared for audits without assigning extra work.
Enhance Your Development Security With Legit
Even the best container security tools only cover part of the picture. Legit Security extends that protection to everything that happens before code reaches your containers, securing your pipelines and cloud environments.
With Legit’s application security posture management, you get visibility into every stage of the software development lifecycle, connecting vulnerabilities in source code and infrastructure back to the teams and commits that introduced them. Legit also unifies data from your scanner and runtime tools, in order to correlate findings across repositories and build systems to prioritize what matters most.
Request a demo today to see how Legit strengthens your container security posture with complete visibility.
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