A vulnerability in WhatsApp Desktop versions prior to 0.3.9309 when paired with WhatsApp for iPhone versions prior to 2.20.10 allows cross-site scripting and local file reading. Exploiting the vulnerability requires the victim to click a link preview from a specially crafted text message.
https://www.facebook.com/security/advisories/cve-2019-18426
http://packetstormsecurity.com/files/157097/WhatsApp-Desktop-0.3.9308-Cross-Site-Scripting.html