Modern development lives in containers. They’re fast, scalable, and efficient, and they now power nearly 90% of cloud-native applications globally. But just like any technology, containers introduce a new breed of security challenges.  

From outdated base images and misconfigurations to runtime drift and exposed secrets, container security risks grow at every stage of the SDLC, and fixing them in production can cost up to 30x more than catching them early. 

In our recent webinar, AppSec experts from Checkmarx break down the most common misconceptions around container security and show how to avoid costly mistakes with a smarter, layered approach. 

Here’s a quick rundown of the key takeaways. 

Misconception 1: “We already scan the code. We’re covered.” 

The Reality: Scanning your codebase with tools like SAST or SCA is just the beginning. Once code is containerized, it can pull in unseen dependencies, packages, and configuration risks during build time, things that simply aren’t visible in the repo. 

Why it matters: 

• Build-time actions can introduce hidden vulnerabilities. 

• Dependencies may be pulled from untrusted or outdated sources. 

• Scanning only the repo leads to false positives (chasing what never deploys) and false negatives (missing real risks). 

The fix: What you see in the repo isn’t always what you get in the final image. Scan the fully built container image, not just the codebase or Dockerfile. This reveals what’s going to run, including hidden packages, malicious layers, and runtime-only risks, giving you a truer picture of what’s going to run in production. 

Misconception 2: “Our base images are from Docker Hub, so they’re safe.” 

The Reality: Just because an image comes from Docker Hub doesn’t mean it’s secure. Public registries are full of outdated, unmaintained, or even malicious images, including some that look official, and many containing tens of thousands of known vulnerabilities. No matter how trusted the source feels, we can’t take it as face value. 

Why it matters: 

• Typosquatting is real: attackers create images that mimic popular ones to exploit developer trust. 

• Even popular images often carry hundreds of known vulnerabilities. 

• Many haven’t been updated in 2+ years, leaving them wide open to known exploits. 

The fix: Scan early, scan often, and treat base images like any other dependency in your supply chain. Tags like “Docker Official” or “Verified Publisher” help as they go through additional vetting, but they’re not foolproof. Always scan base images before building on top of them and maintain a pre-approved image library to reduce risk across teams. 

Misconception 3: “If we patch known vulnerabilities, we’re secure.” 

Reality: Most container breaches don’t happen because of unpatched CVEs, they happen because of misconfigurations. While patching is critical, it’s not enough. Misconfigurations are just as dangerous as unpatched code. And they’re often even easier to exploit. Containers and Kubernetes environments often fall victim to security gaps like containers running as root, secrets hardcoded in code or config files, and clusters with overly permissive roles or unnecessary exposure.  

Why it matters:  

• Privilege escalation. If a container is running as root or has more access than it needs, it’s like handing over the master keys. From there, attackers can move laterally and gain full control. 

• Data exposure. A single hardcoded secret or exposed config file is all it takes. Suddenly, attackers have direct access to your databases, APIs, or internal services. 

• Resource hijacking. Think crypto mining, service abuse, or denial of service. All made possible just because a resource limit wasn’t set correctly. 

The fix: Treat misconfigurations with the same urgency as vulnerabilities. To help prevent these kinds of misconfigurations before they hit production, we built KICS, an open source tool that scans Terraform, Kubernetes, Docker, and other IaC files for security risks and compliance gaps. It supports over 2,400 checks out of the box, is highly customizable, and plugs easily into CI/CD pipelines. 

For leaked credentials, 2MS (Too Many Secrets) goes a step further, scanning not just your code files, but applications like Slack channels, Confluence docs, and more 

Misconception 4: “We’ll catch it all with runtime scanning.” 

The Reality: Relying only on runtime scanning is like locking the door after the intruder has already walked in. Yes, runtime security, monitoring, intrusion detection, anomaly alerts, is critical. But if that’s your first line of defense, you’re reacting too late. 

Why this matters: 

• The average time it takes to patch a vulnerability? 38 days 

• The average time it takes attackers to exploit a new one? Just 12 days 

That’s a 26-day head start for attackers, and they don’t wait for your next sprint. When vulnerabilities are found too late, the damage goes beyond just code: 

• Fixing issues in production costs up to 30x more than catching them earlier. 

• Delays lead to business disruption, customer trust issues, and possible regulatory penalties 

The fix: Adopt a defense-in-depth strategy. Runtime tools are your last line of defense,  not your only one. The earlier you catch issues, the safer (and cheaper) your containers will be. Scan early, scan often, and cover all stages of your SDLC, not just production. 

Build a Smart Container Security Workflow 

Container security can’t wait for the end of the pipeline, it needs to be built in across the entire SDLC. Start by scanning base images before you even write code, so you don’t embed insecure dependencies from day one. Then scan again before production, after the image is fully built, because that’s the real artifact that will run. And even post-deployment, security matters. Misconfigured containers or missing runtime controls can still expose you to risk. Scan your infrastructure and container configs for drift, secrets, and misconfigurations. 

A good rule of thumb is to treat container security as a continuous process, not a point-in-time event: 

• During every build: Scan images before deployment to catch misconfigs & known CVEs early 

• Nightly/Weekly: Rescan registry images for newly disclosed CVEs to detect vulnerabilities introduced after deployment 

• Quarterly: Perform full Docker security assessments or Kubernetes security audits including access control, policy enforcement, and network segmentation 

• After major changes: Trigger a fresh audit when deploying new services, infrastructure updates, or base image changes 

Dig Deeper into Container Security with Our Full Webinar 

In our expert-led webinar, we take you beyond the surface to break down these misconceptions with practical advice, real-world examples, and into how open source tools like Checkmarx KICS and 2MS help teams keep containers secure.  

Watch the full webinar to dive deeper.