affix - XSS on target config

found in bootstrap 3.3.7

`$('.js-affixed-element-top').affix({
    offset: {
      top: $('.js-page-header').outerHeight(true) - 10
    , bottom: $('.js-footer').outerHeight(true) + 10
    },
    target: '<img src=x onerror=alert(0)>'
  })`

https://jsbin.com/palokaxina/edit?html,output

Win 7 x64
Chrome 67.0.3396.99
Firefox 61.0.1 (64-Bit)