If a contract you’ve interacted with or a token you’re holding has been identified as high-risk, some action is usually recommended. If you’ve approved tokens for expenditure on a vulnerable contract, it may be prudent to revoke such approvals. The option to do so will be provided next to the detailed vulnerability.
Of course, if you believe the risk to be acceptable, no action may be required on your part. Everyone’s risk appetite is different - but the Shield allows you to remain in-the-know of all the potential relevant issues with your wallet(s).