Section "3.8.1. LUKS Implementation in Red Hat Enterprise Linux" [1] needs to be updated. Problem is with following paragraph:
<snip>
The default implementation of LUKS in Red Hat Enterprise Linux is AES 128 with a SHA256 hashing. Ciphers that are available are:

    * AES - Advanced Encryption Standard - FIPS PUB 197
    * Twofish (A 128-bit Block Cipher)
    * Serpent
    * cast5 - RFC 2144
    * cast6 - RFC 2612 
</snip>

Cryptsetup LUKS uses following default compiled-in device cipher parameters:
         plain: aes-cbc-essiv:sha256, Key: 256 bits, Password hashing: ripemd160
         LUKS1: aes-cbc-essiv:sha256, Key: 256 bits, LUKS header hashing: sha1, RNG: /dev/urandom

Text suggested by maintainer:
The default cipher used for LUKS (see cryptsetup --help) is aes-cbc-ssiv:sha256 (AES-256 in CBC mode with vector generator). Note that installator (anaconda) uses by default XTS mode (aes-xts-plain64).

[1] http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/96/html-single/Security_Guide/index.html#sect-Security_Guide-LUKS_Disk_Encryption-LUKS_Implementation