About the Mitigation Tool

How to Apply the UNITY-SEC-844 Mitigation Tool

The Mitigation Tool is a temporary workaround for the Security issue “UNITY-SEC-844” and should not be considered a complete or long term fix/patch of the identified vulnerability. The workaround will disable the identified vulnerable Editor features, but since we can’t control whether the affected functionality becomes re-enabled at some point after applying the workaround (system changes, reinstallations, etc.), we strongly recommend updating to a patched version.

Note: you will no longer be able to use the ‘Open in Unity’ functionality in the web browser version of the Asset Store after applying the workaround.

As part of your remediation plan, review and plan for updating to one of the recommended patches listed at https://unity3d.com/security

Using the Mitigation Tool

This tool will update Windows to mitigate the identified vulnerability. The change is only related to the Unity Editor, and will not affect any other software, including games that use Unity.

Note that reinstalling a vulnerable version of the Editor will undo changes applied by this tool, so you will have to re-run it to ensure mitigation.

Step-Step Installation

  • Download the tool here.
  • Save or Run directly.
  • The tool will request elevation; if you have UAC enabled (on by default in Windows), you should see the application request access for elevation. You should see the Unity logo and the prompt should not be yellow; if it is, press Cancel and make sure you're downloading the tool from Unity's official site: https://unity3d.com/security.
  • Follow the prompts as shown below:
  • If you’ve already applied the mitigation, or for some reason your machine was not vulnerable, the following will be presented:


The tool runs very quickly, you probably won't even see the 'loading' screen. Once it is completed, just press the OK button and proceed to use the Unity Editor as you normally would.

This mitigation will remove the ability for you to open Asset Store assets from an internet browser or an email client. To download these assets, you'll have to navigate to the store from within the Unity Editor.

To get to the Store from within the Editor, you'll find it in the menu under Window->Asset Store:

As mentioned above, the best option is to install the latest patch for your version of Unity (found at https://unity3d.com/security) to ensure you have full functionality of the Editor and are protected through reinstalls.