What is the first action to take upon discovering unauthorized disclosure of classified information?

The immediate priority upon discovering unauthorized disclosure of classified information is to protect that information from further exposure. This step is crucial because it helps mitigate any potential damage that could arise from the initial breach. By securing the information, you prevent additional unauthorized access and limit the risks associated with the dissemination of sensitive data.

Taking this action ensures that any further disclosures are contained, which is vital in maintaining the integrity of classified information and safeguarding national security. Additionally, it allows for a focused response to the incident without further complicating the situation or increasing the potential for harm.

After securing the information, the appropriate reporting channels can be followed, which may include notifying relevant authorities or law enforcement, depending on the severity and nature of the breach. However, immediate containment is the foundational step that enables effective incident response and management.