High (8.8). EPSS 1.4% chance of exploitation in the next 30 days.
The EditingStyle::mergeStyle function in WebKit/Source/core/editing/EditingStyle.cpp in Blink, as used in Google Chrome before 53.0.2785.89 on Windows and OS X and before 53.0.2785.92 on Linux, mishandles custom properties, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted web site that leverages "type confusion" in the StylePropertySerializer class.
Severity
CVSS 3.0
8.8 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
1.4% chance of exploitation in the next 30 days; higher than 72% of CVEs (scores of 2026-10-31)