In addition to the usual array of fixes and improvements to XenForo 1.5, we have also released XenForo Media Gallery 1.1.17 and XenForo Resource Manager 1.2.5.
Significantly, these three releases solve a potential "authentication phishing" exploit inside the SWFUpload library that was reported to us by Julien from
RCE Security. Most browsers either no longer have Flash by default, or mitigate this issue sufficiently, therefore the issue is fairly low risk. However, as a precaution, it is recommended to upgrade.
By upgrading you will be entirely removing SWFUpload from your XF installation. You may remember that over a year ago we
released XenForo 1.5.12 to introduce a new HTML 5 uploader. This may have required add-on developers to update their code to support the new uploader, otherwise SWFUpload would have continued to be used for file uploads in that add-on. In the event that you have add-ons installed which were not updated to use the new uploader, as of this release, these add-ons will no longer support multiple file uploads and instead will only support uploading a single file at a time.