ICU Messages refer to a structured text format developed by the Unicode Consortium, primarily used for internationalization (i18n) and localization (l10n) of software. This format allows developers to manage complex translations, including pluralization, gender adaptation, and variable insertion, in a consistent and secure way. In cybersecurity, ICU Messages are important because improper handling can lead to vulnerabilities such as injection attacks or information leaks. Secure implementation ensures that user-generated content or variables are safely incorporated into messages, minimizing risks. ICU Messages are widely adopted in modern frameworks to provide robust, locale-aware messaging for global applications.