Thread:Project:Support desk/Cannot upload files since the update from 1.22.7 to 1.23./reply

If there's "absolutely no mention of this change anywhere in the change log" I wonder which ChangeLog(s) you checked, because popen has been in the code for a long time. At least long enough that https://git.wikimedia.org/blame/mediawiki%2Fcore.git/HEAD/includes%2FGlobalFunctions.php and https://git.wikimedia.org/blame/mediawiki%2Fcore.git/HEAD/includes%2Ffilebackend%2FFSFileBackend.php do not list the specific commits when it was introduced, once upon a time.