Revoke and change this password, as it is compromised

After downloading several projects into Sonarcloud from GitHub, I received a HIGH security issue titled Revoke and change this password, as it is compromised. The java code is from src/main/resources/application.properties file and it shows user ID and password in clear text.

Does anyone know if this is a mere suggestion not to use clear credentials in the code (as I understand why) or does Sonarcloud actually runs credentials against dark web sources?

SonarCloud does not run the credentials against dark web sources. It just assumes that if the credentials have been leaked into your repository, they ought to be revoked.