Works,
as I didn't want to patch my local CGI.pm, I've put this workaround into my code:

my $upload_meta = $q->uploadInfo($form->{filename});
my ($filename) = $upload_meta->{'Content-Disposition'} =~/ filename=((
+"(?:\\\"|[^"])*")|([a-z\d!\#'\*\+,\.^_\`\{\}\|\~]*))/i;
substr($filename,0,1,''); chop($filename); $filename =~ s/\\"/"/g;
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