The Sprint variant was updated to 4.4.3 last week. I also see on the XDA landing page that HTC released 4.4.3 developer edition for the M7.
I know everyone thought they would skip it and go to 4.4.4 but I guess they already had some 4.4.3 in the pipeline and felt it made sense to release it.
That probably means that thos devices will have to wait for 5.0 and they will skip 4.4.4.
Originally Posted by Reyzis
There is no official 4.4.3 for the HTC One.
I think, they will update the Module when HTC release the official 4.4.3 update.