HOUSTON – Turns out even former presidents can fall prey to hackers.

A mysterious email hacker apparently accessed private photos and messages sent between members of the Bush family, including both retired commanders in chief.

The Secret Service is investigating the breach, which appeared to yield little more than a few snapshots and some family discussions. But the incident illustrated how easily hackers can pry into private lives, even those of one of the nation’s most prominent and closely guarded political clans.

The Smoking Gun website displayed photos it said came from the hacker, including one that purported to show the elder Bush during his recent stay in a Houston hospital, where he spent almost two months undergoing treatment for complications from a bronchial infection.

The website said the hacker, who went by the online moniker “Guccifer,” gained access to the material through Bush family members and friends.

That could have made George W. Bush and George H.W. Bush vulnerable, even if they have the finest security that technology can provide. A friend or relative who clicked on a deceptive link or unwittingly downloaded a suspicious program might accidentally have exposed correspondence involving the former presidents.

“We can’t control what our friends do,” said Dan Wallach, manager of Rice University’s computer security lab. “If my friends post a photo of me on Facebook, I can untag myself, but I can’t delete it. It’s not my photo. And that’s just a general-purpose problem.”

Reached by email, former Florida Gov. Jeb Bush called the hacking “outrageous.”

The rest of the family stayed quiet.

“There’s a criminal investigation and, as such, there’s nothing else we can say,” said Jim McGrath, a spokesman for George H.W. Bush.