WhatsApp’s web-based extension of the popular instant messaging app is vulnerable to an exploit that could allow hackers to trick users into downloading malware on their computers in a new and more sophisticated way. The WhatsApp security team has verified and acknowledged the vulnerability and has rolled out an update to fix the issue in its web clients. The flaw affects all versions of WhatsApp before V0.1.4481. So, users are advised to make sure that they are running the fully updated version of WhatsApp.
Source: https://thehackernews.com/2015/09/whatsapp-vcard-vulnerability.html