Microsoft Skype for Business Server 2015: January 2018

Microsoft released Skype for Business Server 2015, v6.0.9319.514 - not public.
See description in KB4074701 and contact Microsoft Support to get the download

Skype for Business 2016: January 2018

Microsoft released Skype for Business 2016, v16.0.4639.1001
See description in KB4011623 and download from here x86 or x64

Microsoft Lync 2013 / Skype for Business 2015: January 2018

Microsoft released Lync 2013 / Skype for Business 2015, v15.0.4997.1000
See description in KB4011638 and download from here x86 or x64

Exchange Server 2016 CU8 UM Language Packs

Microsoft released Exchange Server 2016 CU8 UM Language Packs, v15.01.1415.002
Download from here

Cumulative Update 8 for Exchange Server 2016

Microsoft released Exchange Server 2016 Cumulative Update 8, v15.01.1415.002
See description in KB4035145 and download from here

Cumulative Update 19 for Exchange Server 2013

Microsoft released Exchange Server 2013 Cumulative Update 19, v15.00.1365.001
See description in KB4037224 and download from here

Exchange Server 2013 CU19 UM Language Packs

Microsoft released Exchange Server 2013 CU19 UM Language Packs, v15.00.1365.001
Download from here