Updated: LinkedIn says it hasn't yet identified a security breach.
LinkedIn users could be facing yet another security problem.
A user in a Russian forum says that he has hacked and uploaded almost 6.5 million LinkedIn passwords, according to The Verge. Though his claim has yet to be confirmed, Twitter users are already reporting that they've found their hashed LinkedIn passwords on the list, security expert Per Thorsheim said.
LinkedIn revealed through its own tweet that it's looking into reports of stolen passwords, and it advised users to stay tuned for more information.
Many of the hashes include the word "linkedin," which The Verge believes lends credibility to the reports.
LinkedIn passwords are encrypted using an algorithm known as SHA-1, which is considered very secure. Complex passwords will likely take some time to decrypt, but simple ones may be at risk.
Sophos security expert Graham Cluley is advising LinkedIn users to change their passwords as soon as possible, at least as a precaution. If the report is true, then hackers are undoubtedly working hard to decrypt the hashed, or unsalted, passwords.
"Although the data which has been released so far does not include associated email addresses, it is reasonable to assume that such information may be in the hands of the criminals," Cluley added.