We have just released version 3.27.9 of MetaSlider. We recommend updating to this version because it fixes a security issue that was reported to us.
The reported issue does require the user to be logged in as an Administrator user. This might seem confusing: if a user is already an Administrator, what more harm can they can cause? However, the MetaSlider team take all security issues incredibly seriously and made sure to fix this. If you want more details, WPScan has a good post on why Administrator issues are still valid.
After this report, we also gave the plugin a full code review and wherever possible, we added further security checks. The full changelog is available on WordPress.org.
If you ever have a security question or issue with MetaSlider, please click for details on how to contact us.