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run code in 200+ php & hhvm versions
Bugs & Features
<?php $regex = '/((a*)|(?=ab\K))/'; $subject = "aaaaxyzaabaa"; // Comment/uncomment below as wanted. // All 3 functions are vulnerable (note, other functions are affected as well) $x=preg_replace($regex, '\0',$subject); var_dump($x);
based on 3qb8O
Output for 5.3.18 - 7.2.0
string(12) "aaaaxyzaabaa"