CBO Hit by Suspected Nation-State Cyberattack

Nation-State Actor Suspected in Breach of Congressional Budget Office Chris Riotta (@chrisriotta) • November 7, 2025

The U.S. federal agency that advises Congress on the cost and economic impact of legislation has been hit by a cyberattack, officials confirmed Friday.

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The Congressional Budget Office said it identified a "security incident" and "has taken immediate action to contain it" after reports indicated a suspected nation-state actor breached its systems. CBO did not attribute the attack to any specific threat actor and said the investigation is ongoing.

CBO "has implemented additional monitoring and new security controls to further protect the agency's systems going forward," CBO Chief of Media Communications Caitlin Emma said in an emailed statement. She did not provide details surrounding the apparent breach, and declined to answer follow-up questions.

The agency ...