{"id":"CVE-2026-49210","aliases":["GHSA-38x5-rcv4-xf7x"],"url":"https://o3.security/vulnerability/CVE-2026-49210","summary":"Symfony UX: XSS in symfony/ux-live-component via attacker-controlled child component tag","details":"Symfony UX is a JavaScript ecosystem for Symfony. From 2.8.0 until 2.36.0 and 3.1.0, Symfony\\UX\\LiveComponent\\Util\\ChildComponentPartialRenderer::createHtml() interpolates the client-controlled children[id].tag value from LiveComponentSubscriber and InterceptChildComponentRenderSubscriber directly into HTML as a tag name without escaping or validation, allowing arbitrary HTML, including <script> tags, on any Live Component re-render that contains at least one child component. This issue is fixed in versions 2.36.0 and 3.1.0.","published":"2026-07-17T16:09:17.850Z","modified":"2026-08-12T03:51:13.091750469Z","cvss":null,"epss":{"score":0.00338,"percentile":0.26922,"asOf":"2026-09-12"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"symfony/ux-live-component","fixedVersion":"2.36.0"},{"ecosystem":"Packagist","name":"symfony/ux-live-component","fixedVersion":"3.1.0"}],"fix":{"url":"https://github.com/symfony/ux/commit/fbc5e9a1bda7e4556be21bb1d970f382760ed9a9","label":"symfony/ux@fbc5e9a"},"references":[{"type":"WEB","url":"https://github.com/symfony/ux/releases/tag/v2.36.0"},{"type":"WEB","url":"https://github.com/symfony/ux/releases/tag/v3.1.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49210.json"},{"type":"ADVISORY","url":"https://github.com/symfony/ux/security/advisories/GHSA-38x5-rcv4-xf7x"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49210"},{"type":"FIX","url":"https://github.com/symfony/ux/commit/fbc5e9a1bda7e4556be21bb1d970f382760ed9a9"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:13.091750469Z"}}