GHSA-mwqm-4fw3-cjvr symfony/ux-autocomplete: XSS via unescaped AJAX response data

• Packagist symfony/ux-autocomplete: >= 2.2.0, < 2.36.0 → fixed in 2.36.0 • Packagist symfony/ux-autocomplete: >= 3.0.0, < 3.1.0 → fixed in 3.1.0

Description The Stimulus controller shipped with `symfony/ux-autocomplete` renders AJAX response items into the dropdown by interpolating the `text` field directly into HTML template literals (`${item[labelField]}`) inside `_createAutocompleteWithRemoteData()`. The value is parsed as HTML rather than text, so any markup contained in the AJAX response is executed by the browser. When the dropdown values are derived from user-supplied content, an attacker can craft a string that triggers stored XSS in the browser of any other user who later opens a page containing an autocomplete widget backed by the same data. Resolution The `option` and `item` renderers used in `_createAutocompleteWithRemoteData()` now use TomSelect's `escape` helper to HTML-escape the value by default. Endpoints that legitimately return HTML (for example, to highlight the search term) can opt back in to the previous behavior by setting `options_as_html: true`. The `AutocompleteChoiceTypeExtension` normalizer that previously forced `options_as_html=false` when `autocomplete_url` was set has been dropped so the opt-in is reachable from the form layer. The patch for this issue is available here for branch 2.x (and forward-ported to 3.x). Credits Symfony would like to thank Alex Ashkov for reporting the issue and Hugo Alliaume for providing the fix.