Article 17 refers to the Italian NIS2 provision that governs formal cybersecurity information sharing with suppliers and partners. In practice, it covers relationships where an organization exchanges security-relevant data with a SOC, MDR provider, test lab, red team, or threat-intelligence partner. The key issue is not the vendor label, but whether the service involves controlled transfer of security information that needs legal and operational oversight.
This matters because the shared material can include logs, alerts, findings, indicators of compromise, exploit evidence, and remediation notes. If access is too broad or retention rules are unclear, sensitive defensive data can become part of the attack surface. In security operations, Article 17 pushes organizations to define agreements, limit what is shared, track who joins or leaves the arrangement, and handle required notifications to the competent authority. Used well, it helps turn supplier collaboration into a governed security control rather than an unmanaged data channel.