CVE-2026-45753 Symfony: HtmlSanitizer UrlAttributeSanitizer Omits action/formaction/poster/cite — javascript: URI Survives Sanitization (XSS)

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, UrlAttributeSanitizer::getSupportedAttributes omits URL-valued attributes including action, formaction, poster, and cite, so configurations that adm...