Legal actions are bankruptcies and judgments. You can see any legal actions you're facing under the 'Personal' section of your credit report.
Bankruptcy
Bankruptcy is a way for you to deal with debts you can't pay.
Judgments
A judgment is an order placed by the court. A provider can apply for a judgement from the court for you to repay the debt you owe.
If you pay the debt back it'll show as 'Satisfied'.
If you don't pay a judgment it'll show as 'Unsatisfied' in your report.
How these affect your score
The above can indicate that you’re struggling to pay back the money you owe and have a negative affect on your score.