Oracle Founder and Chairman Larry Ellison confirmed Hurd's death Friday.
"Mark was my close and irreplaceable friend, and trusted colleague," Ellison said in a memo to Oracle employees that was posted on Mark Hurd's personal website. "Oracle has lost a brilliant and beloved leader who personally touched the lives of so many of us during his decade at Oracle. All of us will miss Mark's keen mind and rare ability to analyze, simplify and solve problems quickly."
Hurd took a leave of absence from Oracle (ORCL) a month ago for unspecified medical reasons. At the time, he said in a message to employees: "I've decided that I need to spend time focused on my health." He had been a chief executive and board director at the company since 2014. He served alongside Safra Catz, who also has the title of CEO. Ellison took over Hurd's responsibilities when he left.
Hurd's Oracle career started in 2010, one month after he resigned as Hewlett-Packard's CEO over sexual harassment allegations. HP claimed that he failed to tell the board about a "personal relationship" with actress Jodie Fisher, who was working as a marketing contractor for the company.
In 2010, Oracle boss Ellison slammed HP for letting go of Hurd, calling it "the worst personnel decision since the idiots on the Apple board fired Steve Jobs many years ago." He then hired Hurd on as president, sharing the position with Safra Catz.
HP (HPQ) later said in a regulatory filing that an outside investigation of the claims "determined that there was no violation of HP's sexual harassment policy, but did find violations of HP's Standards of Business Conduct." Hurd conceded in the HP press release that "there were instances in which I did not live up to the standards and principles of trust, respect and integrity that I have espoused at HP."
Hurd walked away from HP with $12 million in cash and a large portion of his stock options.
Oracle is one of HP's chief rivals, and the companies have a long history of litigation and nastiness. Hurd's appointment ruffled some feathers in Silicon Valley.
HP didn't make it easy for Hurd to make the jump: It sued Oracle in an attempt to stop Hurd from joining. In court documents filed in 2010, HP said it believed Hurd had put its "most valuable trade secrets and confidential information in peril."
But Oracle needed an experienced salesman as Amazon (AMZN), Microsoft (MSFT) and Google (GOOGL) began to grow their cloud computing businesses. That left Oracle's middleware and database products looking particularly outdated.
Since Hurd's arrival, the company has greatly expanded its cloud computing portfolio, although Oracle still trails its competitors by a wide margin. He also started a program to recruit recent college graduates as Oracle salespeople and anticipated the industry's shift toward the cloud.
Hurd was born in 1957 in New York City, on the Upper East Side, according to his personal website. He then moved to Miami for high school. He graduated with a Bachelor's degree in marketing management in 1979 from Baylor University in Texas, where he played tennis and was president of a fraternity.
The tech boss began his career in 1980 at ATM company NCR as a junior salesman. He eventually worked his way up to become CEO in 2003. He became HP's CEO in 2005, replacing ousted CEO Carly Fiorina. Following his jump to Oracle in 2010, he was then promoted to CEO in 2014. He oversaw how Oracle would sell and market products, while Catz handled finance, legal and operations.
Hurd was married to his wife, Paula, for nearly three decades. Paula had worked alongside him at NCR, where she had been a senior executive. They had two daughters and lived in the Bay Area.