Straight out of the WTF department, following their PS4 6.70 Firmware release just a few days ago today Sony pushed yet another PS4 System Software / Firmware 6.71 update with the changelog simply stating "This system software update improves system performance" again. 
As always DON'T UPDATE if you wish to use PS4 game backups and homebrew apps when a new jailbreak exploit arrives, and we'll add any related Tweets below as PlayStation 4 scene developers have a chance to examine it.
Download: PS4 Firmware 6.71 Update (US) / PS4 Firmware 6.71 Update (EU) / PS4 Firmware 6.71 Update (UK) / PS4 Firmware 6.71 Update (AU/NZ) / PS4 Firmware 6.71 Update (JP)
Changelog:
About PlayStation 4 system software version 6.71
Main features in version 6.71 update
Here are some guides for those new on How to Block PS4 Firmware Updates, How to Delete Downloaded PS4 Update PUPs that haven't been installed yet, How to Update to a Specific PS4 Firmware and also some PS4 HEN Update Blocker Payloads.
From Pastebin.com:
From ChendoChap via PS4 Kernel Build Strings:

Download: PS4 Firmware 6.71 Update (US) / PS4 Firmware 6.71 Update (EU) / PS4 Firmware 6.71 Update (UK) / PS4 Firmware 6.71 Update (AU/NZ) / PS4 Firmware 6.71 Update (JP)
Changelog:
About PlayStation 4 system software version 6.71
Main features in version 6.71 update
- This system software update improves system performance.

Code:
6.71 PS4 !
Twitter : https://twitter.com/ImMrNiato
release: 0x06710001
build: cex
security-repository-path: release_branches/release_06.710
security-revision: 10002
sys-repository-path: release_branches/release_06.710
sys-revision: 125276
***-internal-build-number: 111323
middleware-repository-path: release_branches/release_06.710
middleware-revision: 21971
middleware-build-number: 71548
vsh-repository-path: release_branches/release_06.710
vsh-revision: 181684
vsh-build-number: 1135981
Code:
| CEX || 6.71 || r125276/release_branches/release_06.710 May 31 2019 19:39:22 || dumped