Ferran Obiols developed a header-based NotFoundResolver detection feature for the projectdiscovery/nuclei-templates repository, focusing on improving the identification of dangling CNAME takeovers within HubSpot infrastructure. Leveraging YAML for template creation and applying network security and security testing expertise, Ferran replaced body-based checks with logic that inspects HTTP response headers, addressing previous detection gaps and reducing false negatives. The implementation included evidence extractors to capture relevant signals, resulting in more reliable detection coverage and faster remediation cues. This work enhanced the maintainability and effectiveness of nuclei-templates, demonstrating a thoughtful approach to template design and security automation within a short timeframe.