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.
Severity
CVSS 3.0
9.6 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS
1.3% chance of exploitation in the next 30 days; higher than 70% of CVEs (scores of 2026-10-31)