For legitimate study, you can find used copies of the third edition or invest in the more recent updates required for the current exam.
The CISSP exam is updated every three years (most recently in April 2024 ) [1, 6]. Using an older "Third Edition" means studying obsolete domains and missing critical new topics like Software Defined Networking (SDN) or updated Cloud Security frameworks [1, 3]. For legitimate study, you can find used copies