If you're a Windows 10 user who relies on Microsoft Edge as your primary browser, this security warning doesn't apply to you. But for anyone who is not using Edge exclusively -- heads up. Disable Flash because is a major attack vector for a security flaw in Windows.
The exploit is a combination of the win32K system and Adobe's Flash, and hackers are already actively using it.
Microsoft will have a full patch ready on November 8, 2016. In the meantime, you can disable Flash in Internet Explorer by doing this:
1. Time to manage the add-ons. Do this by clicking the gear icon in the upper right-hand menu and selecting “Manage add-ons.”
2. Select “Shockwave Flash Object.” .
3. Hit disable.
In Firefox, follow these directions:
1. Type “about:addons” in the URL bar.
2. Select the plug-ins icon in the resulting menu.
3. Find Shockwave Flash and switch to "Never Activate."
In Chrome, follow these directions:
1. Type “chrome://plugins” in the URL bar.
2. Select the Adobe Flash Player plug-in.
3. Click disable
As to why Edge users are safe? Because EVP Terry Meyerson says so.