A flaw in popular messenger apps WhatsApp and Telegram , which could allow hackers to gain access to hundreds of millions of accounts using the very encryption software designed to keep them out , has been discovered Vulnerability-related.DiscoverVulnerability by cyber security firm Check Point . The Israeli multinational said it was concerned about vulnerabilities in the messaging apps , following WikiLeaks ’ ‘ Vault 7 ’ release of more than 8,500 CIA documents . “ One of the most concerning revelations arising from the recent WikiLeaks publication is the possibility that government organizations can compromise WhatsApp , Telegram and other end-to-end encrypted chat applications , ” the company said in a blog post . These online versions mirror all messages sent and received by a user ’ s mobile device , which deploys end-to-end encryption so that only those sending and receiving messages can view the content . Hackers could gain access to a user ’ s account , however , by booby-trapping a digital image with malicious code which would be activated once the image is viewed . The code could then spread like a virus by sending infected messages to a user 's contacts . “ This means that attackers could potentially download your photos and or post them online , send messages on your behalf , demand ransom Attack.Ransom , and even take over your friends ’ accounts , ” they added . Check Point said Vulnerability-related.DiscoverVulnerability it alerted Vulnerability-related.DiscoverVulnerability both companies to the problem last week and waited for the issues to be resolved Vulnerability-related.PatchVulnerability before making it public . Both companies have said they ’ ve since patched the problem . “ Thankfully , WhatsApp and Telegram responded quickly Vulnerability-related.DiscoverVulnerability and responsibly to deploy the mitigation against exploitation of this issue in all web clients , ” Check Point Head of Product Vulnerability Oded Vanunu said . The company has advised , however , that WhatsApp and Telegram web users should restart their browser to ensure they ’ re using the latest versions of the service