Lerkamandarinka Mandarinka focused on enhancing authentication security in the keycloak/keycloak repository by developing Authorization Header Validation Enhancements. Using Java and JUnit, Lerkamandarinka implemented stricter validation logic for Bearer tokens, addressing vulnerabilities such as CVE-2026-0707 and reducing the risk of malformed token exploitation. The work included expanding automated test coverage to cover a range of Bearer token scenarios, ensuring robust backend reliability. By preparing detailed release and security notes, Lerkamandarinka facilitated seamless communication for zero-downtime updates. This targeted feature improved the security posture of token-based authentication flows, demonstrating depth in backend development and security-focused testing practices.