Officials at Skype have released a hotfix (Skype for Mac version 18.104.22.1682), but have not yet pushed the proposed release to all Mac users as there have been no reports of abuse using this method so far.
The Skype vulnerability is also mitigated by the fact that the message would also have to come from someone already on your Skype contact list, as Skype’s default settings don’t allow messages from people you haven’t approved as contacts.
Other Skype clients, such as Windows and Linux, are not susceptible to this vulnerability.
The upcoming Mac Skype release will also feature several other updates and bug fixes. It will be pushed to all Mac users automatically, but if you wish to upgrade to use the hotfix now, click on Skype > Check for Updates or by clicking here.