Why are there 4 critical patches applied per year and are they really necessary for us?

Summary:

Critical patches notifications

Content (please ensure you mask any confidential information):

We receive notification for application of critical patches, 4 times a year. Please see an example in the screenshot below:
subject in mail: [EXTERNAL] Oracle Critical Patch Update for October 2025

Are these patches mandatory? How do we know that we could benefit from them?

Do we need to explicitly request their application in an SR?

Thank you.

Version (include the version you are using, if applicable):

26A

Code Snippet (add any code snippets that support your topic, if applicable):