MapLibre GL JS is an interactive vector tile map library for web browsers. Prior to 6.4.1, DOM.sanitize() in src/util/dom.ts iterates elem.attributes as a live NamedNodeMap while removeAttributes() removes attributes from the same collection, shifting indexes and skipping an adjacent dangerous attribute. An attacker who controls untrusted third-party style attribution strings or user-supplied custom attributions can supply consecutive dangerous attributes, causing an attribute such as onload or ontoggle to survive sanitization and execute when the attribution control inserts the content into innerHTML. A victim must render the affected map content for the script to execute. This issue is fixed in version 6.4.1.

CVE-2026-85061 affects MapLibre GL JS, a web browser vector tile map library, in versions prior to 6.4.1. The vulnerability resides in the DOM.sanitize() function in src/util/dom.ts, which iterates over a live NamedNodeMap while simultaneously removing attributes, causing index shifts that allow dangerous attributes to be skipped. An attacker who controls third-party style attribution strings or custom attributions can craft consecutive dangerous attributes (e.g., onload, ontoggle) that survive sanitization. The surviving event handler attributes are then injected into innerHTML, enabling cross-site scripting (XSS) execution. Exploitation requires a victim to render the affected map content. The vulnerability has been patched in MapLibre GL JS version 6.4.1.