The partial government shutdown may be making some key federal departments and agencies running with skeletal staffs more vulnerable to cybersecurity breaches, experts said.

Meanwhile, the House Homeland Security Committee, which oversees the Department of Homeland Security, said it remains in the dark about how the shutdown has affected the department’s mission to safeguard critical infrastructure from cyberattacks.

“With so many cyber activities reliant on highly skilled contractors required to augment government personnel, government shutdowns significantly degrade the ability of the government function to meet all of their cyber mission requirements,” said Greg Touhill, president of Cyxtera Federal, a company that provides cybersecurity services to the federal government.

He cited security operations, software patching and penetration testing as “essential functions” deferred because of the shutdown.

Even when federal departments designate security operations centers as critical during a shutdown, “they still have gaps covering mission-essential tasks, and many of the smaller agencies affected by the shutdown are unable to maintain the full 24×7 watch coverage,” said Touhill, a retired U.S. Air Force officer who served as the first U.S. federal chief information security officer in 2016.