CVE-2026-55877 Symfony UX: XSS in symfony/ux-icons via unsanitized SVG content in local files and Iconify on-demand responses

Symfony UX is a JavaScript ecosystem for Symfony. From 2.17.0 before 2.36.1 and from 3.0.0 before 3.2.0, the uxicon Twig function is marked issafe='html' and Icon::toHtml inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested...

symfony/ux-icons: XSS via unsanitized SVG content in local files and Iconify on-demand responses

Description The uxicon Twig function is marked issafe='html', so Twig never escapes its output. Icon::toHtml inlines the SVG source verbatim into the page. Browsers execute elements and on event-handler attributes found inside inline SVG, making any unsanitized icon a vector for cross-site...