We're pleased to announce that AnyConnect is macOS High Sierra (10.13) compatible.
Our recommended version for High Sierra is 4.5MR2 (4.5.02033), available today 9/25/17. This version includes additional guidance to ensure that the AnyConnect Kernel Extension (KEXT) is properly approved by the end user. This is a new requirement in High Sierra.
4.4MR4 and 4.5MR1 have also been tested for High Sierra compatibility, but will provide no further guidance to the end user (beyond the single OS prompt) that manual steps are required to provide full AnyConnect capabilities. Additionally, with these older (compatible) AnyConnect releases, a reboot may be required after manually approving the AnyConnect extension to continue to run. This step is not required with 4.5MR2.
Note: Customers using Host Scan must be running version 4.3.5038 or later of the module in order to detect the presence of the macOS 10.13 firewall.
We will continue to look at any way we can optimize this experience in subsequent maintenance releases.