Download iOS 11.2.6 (15D100) for iPhone 6

You will have to note that you can only restore signed IPSW firmware files using iTunes or 3utools.

❌ This IPSW firmware is not being Signed by Apple

Firmware Identifier iPhone7,2
iOS Version 11.2.6
Release Date 2018-02-19
Update Date 2018-02-16
Sha1sum
5d4c6606162b7fadc1907e84e0865ca770a9e4ae
Sha256sum
8705ec9ca2e5383c1c23e64c72ad185d6db1aa03e166377e354db0c1d204ae54
md5sum
e8e55b25c349c4ce0288830bb698b7e5
Size 2.48 GB
FileName
iPhone_4.7_11.2.6_15D100_Restore.ipsw
Status

Download IPSW (2.48GB) Check device info
Release Notes

It should be noted that these are the official release notes for the from Apple

iOS 11.2.6 includes bug fixes for your iPhone or iPad. This update:

For information on the security content of Apple software updates, please visit this website: https://support.apple.com/kb/HT201222