ui/ResultView.js in Wikibase Wikidata Query Service GUI before 0.3.6-SNAPSHOT 2019-11-07 allows HTML injection when reporting the number of results and number of milliseconds. NOTE: this GUI code is no longer bundled with the Wikibase Wikidata Query Service snapshots, such as 0.3.6-SNAPSHOT.

ui/editor/tooltip/Rdf.js in Wikibase Wikidata Query Service GUI before 0.3.6-SNAPSHOT 2019-11-07 allows HTML injection in tooltips for entities. NOTE: this GUI code is no longer bundled with the Wikibase Wikidata Query Service snapshots, such as 0.3.6-SNAPSHOT.

In Wikibase Wikidata Query Service GUI before 0.3.6-SNAPSHOT 2019-11-07, when mathematical expressions in results are displayed directly, arbitrary JavaScript execution can occur, aka XSS. This was addressed by introducing MathJax as a new mathematics rendering engine. NOTE: this GUI code is no longer bundled with the Wikibase Wikidata Query Service snapshots, such as 0.3.6-SNAPSHOT.