In this summary, we discussed various strategies to disable XXE (External XML Entity) processing in different contexts, including disabling DOCTYPE declarations, external entities declarations, and entity reference expansions. Disabling these features can prevent XXE vulnerabilities, which are potential security risks that allow an attacker to inject malicious content into an XML document. The approach depends on the project needs, with some solutions being more restrictive than others. For example, in Java, disabling DOCTYPE declarations or external entities declarations can be done using specific features and settings. Additionally, enabling secure processing through the Java JAXP Feature for Secure Processing (FSP) can also help prevent XXE vulnerabilities. However, not all XML processors support FSP, so additional measures may be necessary to ensure security. Overall, understanding how to configure an XML parser to prevent XXE vulnerabilities is crucial for securing applications that process XML data.