Please do not update to 3.9.9 and wait for 3.9.10.
More information can be found here: https://github.com/joomla/joomla-cms/issues/25482
Joomla 3.9.9 is now available. This is a security fix release for the 3.x series of Joomla which addresses one security vulnerability and contains over 30 bug fixes and improvements.
What's in 3.9.9?
Joomla 3.9.9 includes one security vulnerability fix and several bugs and improvements, including:
Security Issues Fixed
- Low Priority - Core - Filter attribute in subform fields allows remote code execution (affecting Joomla 3.9.7 through 3.9.8 ) More information »
- Repeatable Custom Fields: fix to keep HTML tags #25189
- Media Manager: Modal layout improved #22475
- Voting: Cache cleaned after voting #25201
- Article ordering: Items grouped by category first #25295
- Batch system: Improvements for Contact and Newsfeed #25259
Full announcement + download links: https://www.joomla.org/announcements/re ... lease.html
Discussion Forum: viewtopic.php?f=9&t=972985