CVE-2026-55877: Symfony Ux

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

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 ux_icon() Twig function is marked is_safe=['html'] and Icon::toHtml() inlines SVG source verbatim, allowing unsanitized local SVG files or Iconify on-demand JSON body responses containing nested script elements, on* event handlers, or dangerous URL schemes to execute cross-site scripting. This issue is fixed in versions 2.36.1 and 3.2.0.

Affected products

• Symfony Ux: from 2.17.0, before 2.36.1 (fixed in 2.36.1); from 3.0.0, before 3.2.0 (fixed in 3.2.0)

Published 2026-07-08. Last modified 2026-08-19.