Use-after-free vulnerability in WebKit/Source/core/editing/VisibleUnits.cpp in Blink, as used in Google Chrome before 52.0.2743.82, allows remote attackers to cause a denial of service or possibly have unspecified other impact via crafted JavaScript code involving an @import at-rule in a Cascading Style Sheets (CSS) token sequence in conjunction with a rel=import attribute of a LINK element.