The recently published WordPress version 4.7.3 fixes various bugs and six security issues.
WordPress 4.7.3 was released on March 6. The new version contains security and bug fixes. You find detailed information about WordPress 4.7.3 in the release post on WordPress.org.
Dev chat from March 8
First meeting topic was the recently released WordPress 4.7.3 and the upcoming version 4.7.4, which will be lead by Pascal Birchler. After that, the core team discussed browser support for the new editor again. The preliminary result is that the majority agree to drop support for older IE versions. The fallback question has to be further discussed — it would also be possible to use a mix like Jeffrey Paul suggested:
The TinyMCE team would also like to drop support for old IE versions.