CS0-004 study resources: free official sources
The best CS0-004 resources are free and come from the bodies that define the concepts: CompTIA for the exam scope, NIST for incident handling, MITRE for attacker behaviour, and FIRST and CISA for vulnerability scoring. Read the CompTIA material first to know what is tested, then use the standards below to learn the vocabulary the objectives rely on. One caution: the exam launched on June 23, 2026, so older CySA+ material for CS0-003 will miss newer content such as the AI objective.
Start with CompTIA
The exam page. The CySA+ V4 page states the format (maximum 85 questions, 165 minutes, passing score 750 on a scale of 100 to 900), the recommended experience and an exam objectives summary with the four domains and weights. When this guide was written, the page showed a summary, not a link to the full objectives document. If CompTIA adds the full document, download it and treat it as the master checklist.
CompTIA’s retake and renewal pages. Read the retake policy before booking, and see renewal and retakes for a summary.
Free standards behind the objectives
| Source | Use it for | Matching domain |
|---|---|---|
| NIST SP 800-61 Rev. 3 (April 2025, replaces Rev. 2) | Incident response activities and how they fit risk management | Incident response |
| MITRE ATT&CK | Tactics, techniques and the vocabulary of attacker behaviour | Security operations, incident response |
| CVSS from FIRST | Severity scoring: base and environmental metrics, plus temporal (CVSS 3.x) or threat (CVSS 4.0) metrics | Vulnerability management |
| EPSS from FIRST | A daily probability estimate that a CVE will be exploited | Vulnerability management |
| CISA Known Exploited Vulnerabilities catalog | Vulnerabilities with evidence of exploitation in the wild | Vulnerability management |
How to use them without drowning: read the ATT&CK matrix overview and open five techniques rather than memorising the matrix; read the CVSS metric groups and score two vulnerabilities by hand; compare a CVSS score with an EPSS score for the same CVE and ask which one should move first and why. That comparison is the heart of risk-based prioritisation, covered further in CVSS and vulnerability management.
The Lockheed Martin Cyber Kill Chain is named in the objective summary as well; its stages are described on the company’s public pages and summarised in the incident response domain page.
Lab work
CS0-004 is about reading evidence, so labs should produce evidence to read:
- Scan and rank. Scan a lab VM you own with a free vulnerability scanner, group the findings, patch one and rescan.
- Read packets. Capture traffic in a packet analyser, locate a DNS lookup, a failed login and an unusual outbound connection.
- Build a detection. Send logs to a free SIEM, write a rule for repeated failed logins, then tune it to reduce false positives. See SIEM, SOAR and XDR.
- Walk an incident. Take a public incident write-up and label each step with an ATT&CK tactic and an incident response phase.
- Write a one-page report. Summarise a lab finding for a manager: impact, evidence, action, owner.
Practice questions
Use practice questions to find weak domains, not to memorise answers. The free 20-question practice test is weighted 34/26/24/16 like the domains, and the sample questions show the scenario style.
What to avoid
Braindumps. Leaked or reconstructed exam questions violate CompTIA’s candidate rules and teach recall instead of reasoning, which fails on scenario questions.
Outdated sources. Anything that predates June 2026 may cover CS0-003 only. Check any resource against the four domains on the CompTIA page.
A sensible order
- Read the CompTIA exam page summary once.
- Follow the four-week study plan.
- Study each domain alongside the matching standard from the table.
- Take the practice test and revisit the weakest domain.
- Book when results are consistently strong. See certification costs for budgeting.