Use-after-free vulnerability in WebCore in WebKit before r77705, as used in Google Chrome before 11.0.672.2 and other products, allows user-assisted remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via vectors that entice a user to resubmit a form, related to improper handling of provisional items by the HistoryController component, aka rdar problem 8938557.