An integer overflow that could lead to an attacker-controlled heap out-of-bounds write in PDFium in Google Chrome prior to 66.0.3359.170 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted PDF file.
https://www.debian.org/security/2018/dsa-4237
https://security.gentoo.org/glsa/201805-06
https://chromereleases.googleblog.com/2018/05/stable-channel-update-for-desktop.html