The linked Article is in no way related to that on the 21st. It's more how some Pages show and handle User Input. For the one on the 21st it were roughly fixxed i would say under 30 mins since Dev instantly understood what needs to be fixxed.

Vuln Discovered: ~8:00pm
Vuln Tested: 8:23pm
Vuln Reported: 9:15pm
Call with DAO + Developer: 9:15p for roughly 40 mins
Patched: ~9:24pm

iirc.