Article 6 4.

Information sharing as referred to in paragraph 1 between Cross-Border Cyber Hubs shall be ensured by a high level of interoperability. To support such interoperability, ENISA shall, in close consultation with the Commission, without undue delay and in any event by 5 February 2026, issue interoperability guidelines specifying in particular information-sharing formats and protocols, taking into account international standards and best practices, as well as the functioning of any established Cross-Border Cyber Hubs. Interoperability requirements provided for in the cooperation agreements of Cross-Border Cyber Hubs shall be based on the guidelines issued by ENISA.