Manual:ResetUserTokens.php/en

Details
resetUserTokens.php file is a maintenance script to reset the user_token of users on the wiki. On the one hand it can reset the token for all users. Note that this may log some of them out. Resetting all tokens is not necessary unless you believe your user table has been compromised. On the other hand you can use the script to change those tokens, which currently are NULL. This is useful to improve security for the affected users.