Pass the CKS Certification: Complete Guide

Passing the CKS certification (Certified Kubernetes Security Specialist) requires specific preparation. It's the only Kubernetes certification that requires a prerequisite: a valid CKA. This guide details the complete process, from registration to exam day.

TL;DR: To pass CKS, you must hold a valid CKA. The exam lasts 2 hours, requires 67% to pass, and tests your Kubernetes security skills on a real cluster.

This topic is covered in the LFS460 Kubernetes Security Essentials training.

Mandatory Prerequisite: CKA

Is CKA Really Necessary?

Yes, without exception. According to the official Linux Foundation documentation, you must hold a valid CKA at the time of CKS registration.

See our detailed article: CKS: Is CKA a Mandatory Prerequisite?

What If My CKA Expires Soon?

Situation	Recommended Action
CKA valid > 6 months	Register for CKS
CKA valid 3-6 months	Take CKS quickly
CKA valid < 3 months	Renew CKA first or take CKS immediately
CKA expired	Retake CKA before registering for CKS

CKS is valid for 2 years regardless of your CKA validity. Once CKS is obtained, your CKA can expire without affecting your CKS.

CKS Exam Registration

Step 1: Verify Your Eligibility

Log into your Linux Foundation account and verify that your CKA appears as valid. If your CKA is not visible, contact support before registering.

Step 2: Purchase the Exam

The CKS exam costs $445 USD (Linux Foundation Training). This price includes:

Included	Detail
Exam attempts	2 attempts of 2 hours each
Killer.sh simulator	2 sessions of 36 hours
Registration validity	12 months

To optimize your investment, see our CKS certification cost page.

Step 3: Schedule the Exam

After purchase, you have 12 months to schedule your session. Choose a date allowing sufficient preparation (8-12 weeks recommended).

CKS Exam Process

Exam Format

Aspect	Detail
Duration	2 hours
Questions	15-20 practical tasks
Required score	67%
Environment	Real Kubernetes cluster
Documentation	kubernetes.io allowed

Exam Domains

CKS covers six domains (Linux Foundation Training):

Domain	Weight	Key Skills
Cluster Setup	10%	Network Policies, CIS Benchmarks
Cluster Hardening	15%	RBAC, ServiceAccounts, API Server
System Hardening	15%	AppArmor, Seccomp, kernel
Minimize Microservice Vulnerabilities	20%	Pod Security, OPA
Supply Chain Security	20%	Images, Admission controllers, Trivy
Monitoring, Logging & Runtime Security	20%	Audit, Falco, detection

Technical Requirements

To take the exam:

Browser: Chrome or Chromium only
Screen: Only one screen allowed
Webcam: Functional and positioned to see your face
Microphone: Active for proctor communication
Environment: Closed room, clear desk

Identity Verification

The proctor verifies:

Official ID (passport, ID card)
Name match between ID and registration
Compliant environment (clear desk, empty room)

Strategies for Passing CKS

Time Management

With 2 hours and 67% required, every minute counts:

Phase	Duration	Activity
Initial reading	5 min	Scan all questions
Easy questions	50 min	Secure points
Medium questions	45 min	Go deeper
Difficult questions	15 min	Attempt maximum
Review	5 min	Check answers

Essential Security Commands

# RBAC verification
kubectl auth can-i list pods --as=system:serviceaccount:default:mysa

# NetworkPolicies
kubectl get networkpolicies -A
kubectl describe networkpolicy policy-name -n namespace

# Pod Security Standards
kubectl label ns namespace pod-security.kubernetes.io/enforce=restricted

# Secrets encoding
echo -n 'password' | base64
echo 'cGFzc3dvcmQ=' | base64 -d

# Audit logs
cat /var/log/kubernetes/audit/audit.log | jq .

# Trivy scan
trivy image nginx:latest --severity HIGH,CRITICAL

Security Tools to Master

Tool	Usage	Documentation
Falco	Runtime security	falco.org
Trivy	Image scanning	aquasecurity.github.io/trivy
kube-bench	CIS Benchmarks	github.com/aquasecurity/kube-bench
OPA/Gatekeeper	Policy enforcement	open-policy-agent.github.io

Common Pitfalls to Avoid

Pitfall	Solution
Forgetting namespace	Check `-n namespace` systematically
Overly permissive RBAC	Principle of least privilege
Misconfigured NetworkPolicy	Test with `kubectl exec`
Unscanned image	Always verify with Trivy
Plaintext secrets	Encode in base64 or use external secrets

After the Exam

In Case of Success

Results: Available within 24-48 hours
Certificate: Downloadable PDF from your account
Badge: Credly for LinkedIn sharing
Validity: 2 years (Linux Foundation FAQ)

In Case of Failure

Two attempts are included with registration (Linux Foundation). After receiving results:

Analyze the report by domain
Identify weak points
Intensify targeted practice
Retake Killer.sh
Reschedule within 2-4 weeks

Recommended Preparation

Optimal Path

Step	Activity	Duration
1	Obtain CKA	2-3 months
2	Consolidate in production	1 month
3	LFS460 Training	4 days
4	Intensive practice	4-6 weeks
5	Killer.sh (aim for 75%+)	2 weeks
6	Take CKS	-

Essential Resources

Official training: LFS460 Kubernetes Security Essentials (4 days)
Simulator: Killer.sh (included with exam)
Documentation: kubernetes.io/docs/concepts/security/
Tools: Falco, Trivy, kube-bench, OPA/Gatekeeper

See our CKS preparation guide for a detailed schedule.

CKS Comparison with Other Certifications

Aspect	CKS	CKA	CKAD
Prerequisites	Valid CKA	None	None
Required score	67%	66%	66%
Focus	Security	Administration	Development
Difficulty	High	Medium	Medium

CKS is considered the most difficult Kubernetes certification due to the specialization of the security domain and less documented tools.

Take Action

Passing the CKS certification demonstrates Kubernetes security expertise sought in the market. With 82% of organizations using Kubernetes in production (CNCF Annual Survey 2025), certified Security Specialists are particularly in demand.

Your action plan:

Verify that your CKA is valid
Register for the LFS460 training
Practice security tools (Falco, Trivy, OPA)
Take the exam after 75%+ on Killer.sh

Contact our advisors to plan your path to CKS.

Key Takeaways