Apple is blocking older, buggy versions of Adobe's Flash Player.
Users should update their Safari web browser, and install the latest version of Flash in order to continue using the plug-in, the company recommended in an advisory post.
Adobe released Flash Player 22.0.0.192 to seal holes in the application last week, after security exploits were used against web users in countries such as India, South Korea, China and others.
Users that do not update their Safari browser and Flash plug-in will be presented with the following message: "Adobe Flash Player is out-of-date. The version of this plug-in on your computer does not include the latest security updates and is blocked. To continue using Adobe Flash Player, download an update from Adobe."
The notification will then direct them to where they can download the plug-in.
The news comes as many large tech companies are now moving away from the web plug-in in favour of alternatives.
Firefox blocked Flash Player by default last year in wake of insecurities found in older versions, and Google plans to phase out default support for Flash by the end of the year, as well as binning Flash-based ads by the end of this month.
Apple, too, has announced that, starting with the forthcoming macOS Sierra, it will block Flash Player by default across all websites. Safari 10 will instead attempt to load a HTML5 version of websites, if one is available.
Flash will still be available to users, but they will have manually approve and active for each website they visit. The change is expected later this year, when macOS Sierra launches.
Safari users can update to the latest version of Flash here.
