It said 2.9 million customers were affected, in a story broken by security blogger Brian Krebs.
But on Tuesday, Adobe admitted to Krebs that many more of Adobe's customers were involved: At least 38 million.
"So far, our investigation has confirmed that the attackers obtained access to Adobe IDs and (what were at the time valid), encrypted passwords for approximately 38 million active users," an Adobe spokesperson told Krebs.
And that might not even the end of it. Because Krebs says that he found evidence that hackers could really have access to 150 million user names and passwords. Over the weekend, someone posted a 3.8 GB file to a site used by the hacker group Anonymous that Krebs says looks just like a file he found in September.
In September, he and security professional Alex Holden, of Hold Security, discovered a huge file stashed on a server known to be used by criminal hackers. The file apparently contained a big portion of Adobe's software.
Krebs told Adobe about it and Adobe admitted that someone had also broken into the part of its networks that held user names and credit cards, with 2.9 million customers affected.
Adobe says it has been emailing customers about the breach.
One bit of good news: It doesn't look like hackers got credit card info on all 38 million Adobe customers. We reached out to Adobe and asked and will update if we hear back.
Still, if you use Adobe software, you might want to change your password.