Download iOS 12.5.3 (16H41) 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 12.5.3
Release Date 2021-05-03
Update Date 2021-04-29
Sha1sum
d8c3bca792de9484d3c8aa6f0ad386463882b061
Sha256sum
43fbb5969e5ef9b4af0ca91ec3f88bcc4b44c88604648fe8c04600f4d8538381
md5sum
bc55a4b81db347c1fb423d8972b606f1
Size 2.83 GB
FileName
iPhone_4.7_12.5.3_16H41_Restore.ipsw
Status

Download IPSW (2.83GB) Check device info
Release Notes

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

This update provides important security updates and is recommended for all users.

For information on the security content of Apple software updates, please visit this website:

https://support.apple.com/kb/HT201222