Intel Sandy Bridge-E/EN/EP CPU models (SNB-EP, family 6, model 45, stepping 7)
had issues with MDS-related microcode update that may lead to a system hang
after a microcode update[1][2].  In order to address this, microcode update
to the MDS-related revision 0x718 had been disabled, and the previously
published microcode revision 0x714 is used by default for the OS-driven
microcode update.  The revision 0x71a of the microcode is intended to fix
the aforementioned issue, hence it is enabled by default (but can be disabled
explicitly; see below).

[1] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/15
[2] https://access.redhat.com/solutions/4593951

For the reference, SHA1 checksums of 06-2d-07 microcode files containing
microcode revisions in question are listed below:
 * 06-2d-07, revision 0x                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    