[Q] HTC one android version downgrade

[ursnava]

I have a HTC one At&t unlocked phone. But recently i found that it is now being downgraded to 4.1.2

Android version : 4.1.2
HTC sense 5.0
Software number: 1.26.502.15
SDk : 5.12

It was rooted using TRWP. Dont know when it happend. How to upgrade it to 4.4?

Thanks in advance.