MyBB 1.6.4 Released – Feature Update, Security & Maintenance Release

MyBB 1.6.4 is now available from the MyBB website and is a feature update, security and maintenance release for the 1.6 series.

What’s added/changed in this version?

In 1.6.4, there are 2 new updates and over 100 reported issues fixed.

Please be aware that not all of the existing problems have been fixed in this version. Because of the size of the updates, these will be fixed in a later release.

The 2 new updates included in 1.6.4 are only small – one globally switches on/off plugins and the other detects whether an Administrator has renamed the Portal to check for file verifications.

Security Updates

There are also 3 security updates for 1.6.4. Overall, they are low risk vulnerabilities as they all require administrator permissions – however, one of these is classed as high risk if a user manages to get into the Admin Control Panel (ACP).

As a result of this, it is recommended that only certain types of variables are used in templates that follow the MyBB Development Standards – although other types may be used it the templates are installed to the database through your plugin, Administrators will not be able to save templates with these variables in.

Theme Artists and Plugin Developers should take a close look at the new changes to see if their work will be affected by the new changes and update them accordingly.


In 1.6.4, there are a number of performance-related updates. These range from small code changes to caching thread prefixes. More information about these are available on 1.6.4’s page in the Wiki.

Almost everyone should be able to see at least some benefits from these changes.

Upgrading from 1.6.3 and Other Versions

Due to the size of this release and due to release errors earlier in the 1.6 series, all files need to be changed. This is to ensure that you have the latest versions of the software’s files which can be hard to trace from earlier releases.

This upgrade process is the same for any version of MyBB. Before performing any upgrade, please remember to backup your forum’s files and database and store them safely. If you have edited core files, please make sure you make a changelog for these changes so you can make them again once the upgrade is complete.

If you have installed plugins that require changes to core files, you will need to make those changes again.

To upgrade, follow the Upgrading process. The upgrade script is required. There are also language and theme changes.

If you require support for upgrading to 1.6.4, please see the 1.6 General Support Forum.

Changes in 1.6.4

We’ve made a handy reference guide to what’s changed in 1.6.4 in the Wiki. We’ll be doing this for each version in the future too so you can see what we’re working on.

View 1.6.4 Changes in the Wiki.

MyBB Merge System 1.6.1 Update

For those users who have been using Merge System 1.6.1 and earlier, there is an important security update ready for you.

You can read more about it in the 1.6.1 Update Blog Post.

Thank you,
MyBB Team

21 thoughts on “MyBB 1.6.4 Released – Feature Update, Security & Maintenance Release

  1. Hope this awesome update won’t “break” my current forum, testing. Thank you guys for your work, as always.

  2. FYI we made a few small changes to inc/class_parser.php and install/resources/mybb_theme.xml a few minutes after the release so if you got your download more than a few minutes ago then you might like to download fresh copies of your files. The ACP file check will identify if you have the latest files or not.

  3. Only the Google SEO plugin is affected, I hope soo…
    Then, replacing the inc/functions.php file will do the fix already 🙂

  4. This was a peace of cake to intall, simply upload it to your forum directory and it overrides the existing files, anything extra like templates and plugins will all still be intact. Then simply go into your install directory and run upgrade.php file in your browser example “” but first make sure the lock file is deleted. Follow the steps and boom your done. That easy!

  5. The most amazing free software on the net has just gotten better. It continues to grow..and imagine everything you could want and more all for free. Thank you!

Comments are closed.