Remote frame navigations was incorrectly permitted to local resources in Blink in Google Chrome prior to 71.0.3578.80 allowed an attacker who convinced a user to install a malicious extension to access files on the local file system via a crafted Chrome Extension.
https://www.debian.org/security/2018/dsa-4352
https://security.gentoo.org/glsa/201908-18
https://chromereleases.googleblog.com/2018/12/stable-channel-update-for-desktop.html