Cisco Systems" customers received e-mails Wednesday from the networking company advising them of a security breach of its Web site.
The company said Cisco.com has been compromised and that customers need to change their passwords.
"It has been brought to our attention that there is an issue in a Cisco.com search tool that could expose passwords for registered users," the company warned.
"As a result, to protect our registered Cisco.com users, we"re taking the proactive step of resetting Cisco.com passwords. Needless to say, we"re investigating the incident, which does not appear to be due to a weakness in our security products and technologies or with our network infrastructure."
The company also stressed on its site that the incident appears unrelated to flaws in Cisco products.