President Obama’s transition team improperly ­e-mailed sensitive and confidential information about a candidate for a high-level government job, newly disclosed WikiLeaks e-mails reveal.

Days before Obama won his first term in 2008, a Washington lobbyist circulated an e-mail about James Steinberg, a former Clinton- administration official who was being vetted as Obama’s national security adviser.

The Nov. 2, 2008, e-mail from lobbyist and lawyer Christine Varney contained an attachment with Steinberg’s security-clearance questionnaire. The 61-page document is called a “Questionnaire for National Security Positions (SF86 Format).”

The file was filled with sensitive information, including Steinberg’s Social Security and passport numbers, his mental-health history, details of his marijuana use between 1969 and 1975 while he attended Harvard and Yale, and the adoption of his children in China.

The information was e-mailed to Citibank executive Michael Froman on Obama’s transition team and John Podesta, chairman of Hillary Clinton’s presidential campaign, who headed Obama’s transition team in fall 2008.

“It’s outrageous,” said Matt Mayer, an expert on national security and visiting fellow at the American Enterprise Institute.

Mayer, a former senior official at Homeland Security between 2004 and 2006, filled out a similar form before he was appointed.

“You are disclosing sensitive information that could be used by foreign governments to blackmail you,” he said.

Mayer said the document should have been hand-delivered by staff or by a secure delivery service.

Steinberg, now a professor at Syracuse University, was unbothered that his sensitive information had been shared via insecure e-mails.

“I have no problem,” he told The Post. “I would not be troubled or surprised to have a comprehensive vet and for it to be seen by lawyers for the transition.”

Steinberg was President Bill Clinton’s deputy national security adviser between 1996 and 2001. He was not selected as Obama’s national security adviser, and instead worked directly under Hillary Clinton between 2009 and 2011.