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WHMCS Security Advisory TSR-2016-0001

By David / January 26th, 2016

WHMCS has released new updates for all supported versions of WHMCS. These updates include changes that address security concerns within the WHMCS product.

WHMCS has rated these updates as having a Trivial to Important security impact. Information on security ratings can be found at

Please update your installation to the latest version.

v6.2 - 6.2.1v6.1 - 6.1.2 LTSv6.0 - 6.0.4 LTS
- What is a Patch?
Incremental patches can be downloaded by following the links below.

These patch sets contain only the files that have changed between the previous release and this update. The previous release version that these patch sets are designed for is clearly indicated as the first and smaller number.
6.2.0 --> 6.2.1[SIZE=1]MD5 Checksum: c8cc808c0d0718b13a486ca3dabd4125[/SIZE][/INDENT]

6.1.1 --> 6.1.2[SIZE=1]MD5 Checksum: c6fa1354f9523054d0107866f2e9550e[/SIZE][/INDENT]

6.0.3 --> 6.0.4[SIZE=1]MD5 Checksum: 7d86bb2ca32767f591a8a5c21c81fe6b[/SIZE][/INDENT]

Hotfix for 5.3.14*[SIZE=1]MD5 Checksum: bb5756fe02dc0b99d1a49783afd41dbb[/SIZE][/INDENT]

Need a patch for an older version? Visit our downloads page:

To apply a patch set release, download the files as indicated above. Then follow the upgrade instructions for a "Patch Set" which can be found at

[COLOR="#808080"]* Some installations have yet to upgrade to v6. As a result, we are providing a backport patch for v5.3.14. It is important to remember that v5 is no longer supported. Future security and important maintenance issues will not be patched. We strongly encourage anyone running a version outside of [URL=]Long Term Support[/URL] to upgrade as soon as possible to ensure the performance, accuracy, and security of your business.[/COLOR]

Full Release
- What is a Full Release?
A full release distribution contains all the files of a WHMCS product installation. It can be used to both perform a new installation or update an existing one (regardless of previous version).
6.2.1 Full Version - Download Now[SIZE=1]MD5 Checksum: ff5c9b13a86f9041d52d94ada7e7cac9[/SIZE][/INDENT]

6.1.2 Full Version LTS - Download Now[SIZE=1]MD5 Checksum: 91522bf1d33b20793f1aeb411a588118[/SIZE][/INDENT]

6.0.4 Full Version LTS - Download Now[SIZE=1]MD5 Checksum: ae7695aae719aad249f82a8d86bdbd9c[/SIZE][/INDENT]

To apply a full release, download the release from the URL above. Then follow the upgrade instructions for a "Full Release Version" which can be found at

Security Issue Information

The security changes for the v6.2 release address 2 issues, both of which were reported via the Security Bounty Program.

The security changes for all other releases address 1 issue, which was reported via the Security Bounty Program.

Once sufficient time has passed to allow WHMCS customers to update their installed software, WHMCS will release additional information regarding the nature of the security issues.

Maintenance Issue Information

The v6.2 release also provides resolution for 1 maintenance issue that affected upgrades of EOL versions of the product.

All versioned releases also contain the [URL=]previously released update[/URL] for the Kayako Loginshare and is provided for completeness.

For full details please refer to the changelog:
V6.2.1 - - -[/INDENT]

All published and supported versions of WHMCS are affected by one or more of these maintenance and security issues.

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