I don't know if the CAP CBK / exam / official study guide are due a rewrite, but, even if they are, judging by the order in which these things seem to happen, the official study guide will be the last thing to be updated.
Looking at the book on Amazon published August 2012, the table of contents suggests it's fairly well aligned with the domains listed in the current CAP exam outline document which is dated October 2018:
https://www.isc2.org/Certifications/-/media/ISC2/Certifications/Exam-Outlines/CAP-Exam-Outline-Post-...
Although the more recent reviews on Amazon say the book is out of date, people have been using it to pass the exam along with reviewing the supplemental references - which is standard for ISC2 exams anyway.
As ever, the guidance contained in the exam outline states "Candidates are encouraged to supplement their education and experience by reviewing relevant resources that pertain to the CBK and identifying areas of study that may need additional attention.
View the full list of supplementary references at www.isc2.org/certifications/References."
These are the supplementary references they list:
NIST SP 800-18 Rev 1
NIST SP 800-30 Rev 1
NIST SP 800-37 Rev 1
NIST SP 800-39
NIST SP 800-53 Rev 4
NIST SP 800-53A Rev 4
NIST SP 800-60 Vol1 rev 1
NIST SP 800-64 Rev 2
NIST SP 800-88 Rev 1
NIST SP 800-115
NIST FIPS-199
At least they're all NIST documents you can easily download for free!
I guess you'll need to decide how long it will take you to prepare for and pass the exam? If we're talking under 6 months or so I'd say you don't need to worry about any rewrites.
