Last week the Data Prepper maintainers released two patch updates of Data Prepper. The maintainers strongly recommend updating to using either of these as they have some important security fixes.
1.5.2 - Release 1.5.2 · opensearch-project/data-prepper · GitHub
2.0.1 - Release 2.0.1 · opensearch-project/data-prepper · GitHub
Also, the maintainers recommend updating to Data Prepper 2.0.1 if you are still on the 1.x series. The 2.0 version has some great new features. And only security fixes are being provided to 1.x versions.