A use after free issue exists in WebKit's handling of SVG documents with multiple 'use' elements. Visiting a maliciously crafted website may lead to an unexpected application termination or arbitrary code execution. This issue is addressed through improved handling of 'use' elements in SVG documents.
Red Hat would like to thank Drew Yao of Apple Product Security for responsibly reporting this issue. Upstream acknowledges wushi of team509, working with TippingPoint's Zero Day Initiative, as the original reporter.