Handling of URI action in PDFium in Google Chrome prior to 71.0.3578.80 allowed a remote attacker to initiate potentially unsafe navigations without a user gesture via a crafted PDF file.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2018-12640
https://chromereleases.googleblog.com/2018/12/stable-channel-update-for-desktop.html