NIS2 Implementing Regulation

(16) In order to avoid significant disruption and harm caused by the exploitation of unpatched vulnerabilities in network and information systems, the relevant entities should set out and apply appropriate security patch management procedures which are aligned with the relevant entities’ change management, vulnerability management, risk management and other relevant procedures. Relevant entities should take measures proportionate to their resources to ensure that security patches do not introduce additional vulnerabilities or instabilities. In case of planned inaccessibility to the service caused by the application of security patches, the relevant entities are encouraged to duly inform customers in advance.