403 Forbidden Error On All Websites

Sorry to but on this thread. Having the same problem after updating to V66.0.15

All my cpanel websites show "access denied".

I am the server owner and I have never had this before.

I disabled SPF and firewall, and the problem persists.. it is not a firewall issue.

All the accounts are available (not suspended).

Yet they say ACCESS DENIED.


*edit*

Advancing in the issue, the problem seems to be the PHP handler.. I only see a single one (CGI)..
PHP5.5 works but doesn't load all the content correctly.

PHP7 works.. but I have one critical software still not compatible with PHP7.

PHP5.6 with PFM off doesnt load and gives ACCESS DENIED.
PHP 5.6 works but doesn't load all the content (gives errors in one software)

I checked with my other server, suphp handler is missing.

*edit 2*

Not only the update removed suphp handler, but also despite having the openbase dir turned off globally in cpanel/whm. It was still active.
It took one admin of my managed server company to check and found that one php.ini in the root directory had openbase dir enabled with a =0 function.