ANKARA 

The Trump administration is working to contain the fallout after releasing thousands of pages of documents related to John F. Kennedy’s 1963 assassination, inadvertently exposing sensitive personal data, The New York Times reported Thursday.

Among the 64,000 pages made public by the National Archives, spurred by an unplanned decision by Trump, hundreds contained unredacted Social Security numbers and other private information belonging to congressional staff members, intelligence researchers, and at least one former US ambassador.

According to the report, some of those affected are still alive. Previous disclosures of the same pages had been redacted, with the numbers blacked out, but Trump’s off-the-cuff order on Monday pledged unredacted documents, apparently without consideration of the consequences.

National security lawyer Mark S. Zaid told the Times that the release could breach federal privacy laws, though the legal recourse available to those affected depends on technical details related to government data storage policies.

“Social Security numbers are among the most sensitive data the U.S. government is tasked with protecting,” Zaid said. “This is an egregious breach.”

The White House acknowledged that officials began reviewing the files for exposed personal details only after their publication, not before.

On Wednesday, the administration ordered a review of the records to locate compromised Social Security numbers and directed the Social Security Administration to issue new ones to affected individuals.

Impacted parties will also be provided free credit monitoring, according to a senior official. Likely all of those affected are elderly, a group especially vulnerable to identify theft.

The Times report said even with no redactions, the newly released files do not appear to provide any significant new insights into the assassination, despite the Trump administration high-profile touting of the move.

Historians reviewing the documents found no evidence of a second gunman or revelations supporting conspiracy theories.

Instead, much of the material pertains to US intelligence operations during the Cold War, including CIA surveillance of foreign allies.