WhatsApp has fixed a loophole that allowed one message to render the app unusable for entire groups. The security bug, discovered by Check Point Research, let a single malicious user to allow the app to crash for all members of a group chat by editing message parameters using WhatsApp web interface and browser debugging tool, Engadget reports. WhatsApp patched the issue in September with version 2.19.58. Users are advised to update their apps to prevent the unstoppable crash-loop.