The implementation of the Page.downloadBehavior backend unconditionally marked downloaded files as safe, regardless of file type in Google Chrome prior to 66.0.3359.117 allowed an attacker who convinced a user to install a malicious extension to potentially perform a sandbox escape via a crafted HTML page and user interaction.
https://www.debian.org/security/2018/dsa-4256
https://security.gentoo.org/glsa/201808-01
https://chromereleases.googleblog.com/2018/04/stable-channel-update-for-desktop.html