The No. 2 official in the Cybersecurity and Infrastructure Security Agency’s Cybersecurity Division is leaving the government at the end of the month, in what experts say is a major loss for an agency already struggling amid the Trump administration’s workforce purge.
Matt Hartman, the deputy executive assistant director of the cyber division, announced his departure on Tuesday during a town-hall meeting with his staff, two people familiar with the matter told Cybersecurity Dive. He has been at the Department of Homeland Security since 2010 and has overseen the day-to-day operations of CISA’s largest and best-known division since February 2021. Hartman’s team is responsible for threat hunting on government networks, providing security services to other federal agencies, analyzing and reporting on new vulnerabilities and managing the Joint Cyber Defense Collaborative. He has served as acting head of the cyber division from the beginning of the Trump administration until Trump’s appointment of Karen Evans to lead the division.
“As an expert and leader with the agency's predecessor organization, Matt has been integral to making CISA what it is today,” acting CISA Director Bridget Bean said in a statement. “His leadership, insight, and guidance has shaped the amazing team that remains steadfast in our mission to safeguard the nation’s critical infrastructure against all cyber and physical threats.”
Hartman, who did not respond to a request for comment, is the latest senior CISA official to announce plans to leave the government as part of the Trump administration’s downsizing campaign. Boyden Rohner, the head of the Integrated Operations Division, told her employees in April that she planned to leave.
Chris Butera, the cyber division’s senior technical director, will assume Hartman’s duties, CISA said.
CISA setbacks
During his meeting with staff, Hartman said he was “deeply grateful to everyone here,” according to one of the two people familiar with the matter. The other person said he opened the meeting by expressing confidence in the continued strength of CISA and its cyber mission, pointing to Trump’s Fiscal Year 2026 budget request. (That, however, request would cut CISA’s funding by $491 million.)
Hundreds of CISA employees have either taken buyouts or early-retirement offers or been placed on administrative leave since Trump and Elon Musk’s U.S. DOGE Service launched a campaign to slash the federal workforce. Inside the cyber agency, employees are demoralized, angry at their leadership and worried about the continuity of critical services.
People who worked with Hartman and knew him well said his departure would represent a significant setback to CISA’s operations.
“Matt has been an extraordinary leader for CISA for years,” said Jeff Greene, who led the agency’s cyber division from mid-2024 until the end of the Biden administration. “He's the behind-the-scenes person who's responsible for much of the cyber division's success.”
Ari Schwartz, the managing director of cybersecurity services at Venable and a regular interlocutor with CISA, told Cybersecurity Dive that Hartman was “knowledgeable on a wide range of cybersecurity issues and a thoughtful partner in the public-private partnership.”
Greene, now a distinguished fellow at the Aspen Institute, said Hartman’s exit reflects the cyber wing’s misfortunes under Trump. “The Division has lost a ton of talent,” he said. “There are still some great leaders in the division, and if they can hold onto the team that's still there, it will go forward. But the losses - Matt and more, and those beyond CISA - will have an impact on our overall security.”
Trump officials, Greene told Cybersecurity Dive, “need to stop the bleeding now.”
