How Difficult is the CISSP Exam?
You're looking at the Certified Information Systems Security Professional (CISSP) exam and wondering how hard it is. It's a common question because while the certification has a reputation for being the gold standard, the exam has a reputation for being difficult. Does the exam hold up to its reputation, and what should you expect as you prepare?
Let's take a closer look at the CISSP exam and explore the myths vs reality.
The Exam from 10,000 Feet
The CISSP is one of the most recognized and respected certifications in the field of information security. It’s governed by the International Information System Security Certification Consortium (ISC)², and is designed for experienced security practitioners, managers, and executives.
To become fully certified, you must:
Have at least 5 years of cumulative, paid, full-time work experience in two or more of the 8 CISSP domains.
One year can be waived if you have:
A four-year college degree, or
An approved credential from the (ISC)² list (e.g., Security+, CISA, CISM, CEH, etc.).
👉 If you don’t have the required experience yet, you can still take and pass the exam. You’ll become an Associate of (ISC)² until you gain the necessary experience (you get up to 6 years to earn it).
Type and Format of the Exam
The exam consists of multiple-choice, complex analysis, and scenario-based questions from across eight domains:
Security and Risk Management (weighted 16%)
Asset Security (10%)
Security Architecture and Engineering (13%)
Communication and Network Security (13%)
Identity and Access Management (IAM) (13%)
Security Assessment and Testing (12%)
Security Operations (13%)
Software Development Security (10%)
Time and Number of Questions
You'll have 3 hours to answer a minimum of 100 and a maximum of 150 questions. Each exam includes 25 pre-test, or un-scored questions. To pass or fail, you will need to answer 75 "operational" (or scored) questions. As an adaptive exam, it will adjust the questions to test your level of concept mastery within each of the eight weighted domains. You need to score 700 out of 1000 total possible points to pass.
(ISC)² uses what they call the Confidence Interval Rule (CIR). Basically, this means that once you've reached the 100-question mark, the exam will end when the CAT determines with 95% confidence that you either will or will not pass.
If the CIR hasn’t been invoked prior to 150 questions, at that point, your score and confidence percentage will be assessed, and you’ll be given a pass/fail.
If at the 3-hour mark, the CIR hasn't yet been invoked, CAT will look at the last 75 questions answered and give you a pass/no-pass (if you don't answer 75 scored questions to that point, you automatically fail).
So the minimum number of questions needed for the test engine to determine that you will pass is 100. If you pass at 100 questions, you've shown proficiency in all domains.
What Makes the Exam Difficult?
One of the unique things about the CISSP exam is its Computerized Adaptive Testing (CAT) format. Instead of a more straightforward format like CompTIA’s Security+ exam, the CISSP uses adaptive testing, which adds an additional level of complexity.
What’s different about the CISSP CAT? First, the CAT format only allows forward progress, so you can't mark questions for later review. This means that you need to answer each question and move on.
Secondly, the CAT engine is adaptive. You begin the test with “easy” questions below a passing level. With each answer you provide, based on the difficulty of all questions given, the scoring algorithm re-estimates your ability. After each answer, it determines the next question that it believes you have a 50% chance of answering correctly. With each answer, the CAT's estimate of your ability increases until it determines that you will or will not pass.
Zeroing In On Your Weak Areas
Because of the way the CAT works, it will quickly identify your weakest areas. If you’re an expert in a particular topic, say threat modeling, the exam engine will identify your proficiency in that area, and likely give you only a couple of questions. If you are not as familiar with, say, cryptography, you'll get more questions on that area. The result is that you’ll feel like you're being tested on your weakest areas.
Exam Coverage
The CISSP isn’t your typical memorization and reproduction exam. Instead, it tests the application of concepts, combining a technical understanding with a managerial or ownership approach to protecting the business. The breadth and volume of information covered by the exam can feel overwhelming, as the Office Study Guide is over 1000 pages.
The exam coverage is typically termed a “mile wide and an inch deep.” The truth is that because of the vast knowledge domain, there are going to be many topics that are not included in 100-150 questions. But, because there are thousands of potential questions that could be used based on the body of knowledge, and because the CAT will quickly identify your weakest areas, you really need to study and know the material in all domains. And not just the material itself, but more importantly, how it’s used, and why you would apply it in specific situations.
Question Composition
One of the primary reasons the CISSP exam has a reputation for being difficult is due to the way questions are structured. Questions are designed to test your ability to apply principles from across the domains from the point of view of a manager or business owner. You need to understand the technical components, but you’ll probably be asked questions that seem to have multiple correct answers. You need to choose the best answer based on risk mitigation, its impact on the business, or adherence to security best practices.
This is why mindset is so important, and can make the difference between getting a question right or wrong. Especially when you're deciding between two potentially correct answers.
Myths vs Reality
Myth 1: You need to memorize everything in the Common Body of Knowledge (CBK).
Reality: The CISSP isn’t a memory test. While you should know key terms, frameworks, and models, the exam focuses on applying concepts, not regurgitating details.
Example: Where you’re less likely to see, “What’s the exact block size of AES?”, the exam might ask, “Which encryption method is most appropriate for securing sensitive customer data at rest in this scenario?”
Myth 2: You can pass without really studying or just by doing practice tests.
Reality: The CISSP exam is difficult and requires a sustained, dedicated effort to master the material. Practice tests are valuable for learning the exam style, but they’re not enough on their own. Many practice exams use overly technical questions that don’t match the CISSP’s risk-based, management-oriented approach. Unlike practice exams, it may not be clear what domain a particular question actually tests you on. Many questions may feel novel and require critical thinking, as they involve pulling and applying disparate bits of information from across the CBK.
Myth 3: The exam is about trick questions.
Reality: The questions are challenging but fair. They’re written to test judgment and reasoning, not to trick you. If a question feels tricky, it’s usually because you need to step back and ask: what would an owner or security manager do in this situation?
Myth 4: You can’t pass on your first try.
Reality: It is possible to pass on your first time (and I’ve done it!), but it takes time and effort in preparation. The best mindset to take into the test is that you’ve studied, and you will succeed. If, for whatever reason, that doesn’t happen, you can retake it. Many strong candidates fail on their first attempt — and then pass on the second. The adaptive exam can feel overwhelming, but it’s about persistence and refining your approach.
Exam and Study Tips
(ISC)² learning objectives have a definitive structure and are well thought through, but can initially seem like a jigsaw puzzle. Over time, as you read and absorb the material, you'll start to see patterns emerge. I recommend using multiple study sources because these pieces will start to come together to provide you with an overall view of the material and how concepts are connected.
Remember that the exam tests the application of these combined concepts, as well as judgment and decision-making, rather than just knowledge recall.
👉 It requires mastering in-depth concepts and understanding why one type of control or solution would be used. Often, you'll encounter multiple answers that seem correct, and understanding the nuance of the question and/or the subject matter allows you to choose the most appropriate one.
👉 To give yourself the best chance of passing on your first try, use several different sources to get a balanced perspective. Emphasize the type of study media and modalities that best fit your learning style. Use practice tests to assess your current knowledge level and to find and explore areas of weakness.
👉 You can find additional suggestions and resources in my free CISSP Study Resources repository on GitHub.
FAQ
Q: Is the CISSP exam difficult?
A: Yes, it is considered to be a challenging certification exam to pass, due to the wide knowledge area covered, adaptive testing, and because it demands that you adapt to ambiguity and apply a managerial or leadership mindset.
Q: Is the CISSP only for technical people?
A: The CISSP is a management-level exam, not a purely technical one. It tests whether you can think like a risk manager: balancing risk, business objectives, compliance, and cost.
Q: What is the preparation time needed to pass the CISSP?
A: While it’s possible to pass the CISSP in as little as 3 months, it depends on your cybersecurity experience and knowledge. Most candidates spend between three and six months using a combination of training materials, including study guides, flashcards, and practice tests. It’s important to be consistent in approaching the material, rather than trying to cram it in a short period of time.
Conclusion
While the CISSP is one of the most widely recognized and respected certifications, it can present challenges to even experienced security professionals. The exam’s reputation comes from its wide range of topics, question composition, and its adaptive testing engine.
To give yourself the best chance of passing on your first try, use several different sources to get a balanced perspective. Emphasize the type of study media and modalities that best fit your learning style. Use practice tests to assess your current knowledge level and to find and explore areas of weakness.
Reach out if you need help or want a customized study plan.