A security issue has been discovered that we consider to be of a high severity, and as a result we are releasing an immediate patch to address it.

Although not related to the new release, it is unfortunate timing so soon after the release, but we take security very seriously and so if an issue becomes apparent to us, we will always issue a patch for it as our track record with patches in recent years hopefully demonstrates.

Applying the patch is very simple. It's just one file to update. There are separate versions of the file for each release of WHMCS from V4.0 up to the very latest V5.0 release. The patch download consists of a single file which just needs to be unzipped, and then uploaded to the /includes/ folder replacing the existing file. Download links are as follows:

[INDENT]
Version 4.0.x -> https://www.whmcs.com/members/dl.php?type=d&id=107
Version 4.1.x -> https://www.whmcs.com/members/dl.php?type=d&id=108
Version 4.2.x -> https://www.whmcs.com/members/dl.php?type=d&id=109
Version 4.3.x -> https://www.whmcs.com/members/dl.php?type=d&id=110
Version 4.4.x -> https://www.whmcs.com/members/dl.php?type=d&id=111
Version 4.5.x -> https://www.whmcs.com/members/dl.php?type=d&id=112
Version 5.0.x -> https://www.whmcs.com/members/dl.php?type=d&id=113
[/INDENT]


If you have any questions or need any assistance applying the patch, please do not hesitate to contact us.

We apologize for the inconvenience.

* An email notification is going out to all active license holders
* All client area downloads have been updated to include this by default