A DOMParser XSS issue was discovered in certain Apple products. iOS before 10.3.3 is affected. Safari before 10.1.2 is affected. tvOS before 10.2.2 is affected. The issue involves the "WebKit" component.
https://support.apple.com/HT207924
https://support.apple.com/HT207923
https://support.apple.com/HT207921