An independent researcher has reported a new bug in WhatsApp that could allow anyone to remotely crash most popular messaging app just by sending nearly 4000 emojis to the target user, thereby affecting up to 1 Billion users. The company patched the bug by setting up the limits of characters in WhatsApp text messages, but unfortunately, it failed to set up limits for smileys send via WhatsApp. If you become a victim of such message on WhatsApp, just open your messenger and delete the whole conversation with the sender.
Source: https://thehackernews.com/2015/12/whatapp-crash-bug.html