Security fixes are released for the latest version of OpenScreen. The app updates itself, so please make sure you're on the latest release.
Please do not open a public issue for security problems. Instead, report them privately through GitHub's private vulnerability reporting.
Include what you found, how to reproduce it, and the impact you expect. You'll get a response within a few days, and a fix will be released as soon as it's ready. Reporters are credited in the release notes unless they'd rather not be.