Download iOS 13.1.2 (17A860) for iPhone 11 Pro Max

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 iPhone12,5
iOS Version 13.1.2
Release Date 2019-09-30
Update Date 2019-09-28
Sha1sum
d72ee55f39ba6634536a6858fca0f5e4edcd13f5
Sha256sum
03da692ca4c00ba01cf104c71b6db1b97f935d6a1f3596c9e8dcea9f985f51e7
md5sum
8f0db6e7d0a1f1605702b2508cc8c82e
Size 4.28 GB
FileName
iPhone12,3,iPhone12,5_13.1.2_17A860_Restore.ipsw
Status

Download IPSW (4.28GB) Check device info
Release Notes

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

iOS 13.1.2 includes bug fixes and improvements for your iPhone. This update:

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

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