DUBLIN — A data exposure at Dialog, a private events group cofounded by Peter Thiel, exposed personal information belonging to multiple U.S. national security personnel. The Pentagon is examining the matter, and Dialog's outside counsel has issued a legal demand stating the data was "stolen" and requesting its return.

The exposed individuals include an intelligence official from the National Security Council and an active-duty intelligence officer supporting sensitive military operations. Both were among 222 Dialog event registrants whose private information and login tokens were part of the exposure. The National Security Council official's role involves advising President Donald Trump and the national security adviser on sensitive intelligence programs.

Evidence indicates the files were exposed due to a misconfiguration in Dialog's website that allowed anyone to create an account and access the files by loading a landing page for the group's application. Dialog has internally characterized the incident as a "cyberattack."

The exposed registrants include current and former senior military and national security officials from the United States and its allies. The National Security Council official, a former CIA officer, had a file containing at least two dozen personal details and survey responses. This data included a date of birth, home address, mobile number, headshot photo, and a private authentication token. The file also documented the official's political leanings and how they received an invitation to the invitation-only group. The file included an answer to a registrant questionnaire stating, "future espionage will target your behavior more than your secrets."

The National Security Council official and the active-duty intelligence officer were invited and registered for Dialog's retreat in August, which was held outside Dublin, Ireland. The military intelligence officer's dossier contained the same range of personally identifiable information as the National Security Council official's file. Records identify this individual as an active-duty intelligence officer embedded with a "Tier 1" special operations unit.

Swiss DJ and cybersecurity researcher maia arson crimew provided the initial tip regarding the data exposure. Federal prosecutors indicted maia arson crimew in 2021 on hacking-related charges, but the individual has not been arrested or convicted and has not faced subsequent charges. In 2023, maia arson crimew discovered a copy of the U.S. government's No Fly List on an unsecured server and made it available to some journalists.

The White House requested that the name of the National Security Council official not be published on national security grounds and declined to comment further on the exposure. Dialog did not respond to questions submitted for the story.