Risk: High
A serious security flaw has come to light in Yahoo! Messenger, prompting users to upgrade. The flaw affects all versions of Yahoo! Messenger installed on a Windows PC before 2nd November 2006.
The vulnerability involves an unspecified buffer overflow bug in the IM client's YMailAttach ActiveX control and can potentially allow hackers to take control of Windows PCs by tricking users into visiting maliciously crafted websites.
By updating to the latest version at http://messenger.yahoo.com, users can prevent themselves from being targeted.