powertip.ts in Lila (for Lichess) before ab0beaf allows XSS in some applications because of an innerHTML usage pattern in which text is extracted from a DOM node and interpreted as HTML.
https://github.com/lichess-org/lila/security/advisories/GHSA-9xhx-p3c5-p4v6
https://github.com/lichess-org/lila/commit/ab0beaf0ad671761705d9274663c5dc450608527