{"id":"CVE-2026-50556","aliases":["GHSA-gxx4-3xcv-f8qx"],"url":"https://o3.security/vulnerability/CVE-2026-50556","summary":"Angular: Missing `<noscript>` Raw-Text Serialization Escaping leads to Cross-Site Scripting (XSS) in Angular SSR","details":"A Cross-Site Scripting (XSS) vulnerability exists in `@angular/platform-server`'s DOM emulation dependency (`domino`) when serializing the content of `<noscript>` elements.\n\nWhen rendering dynamic text content inside a `<noscript>` element via template bindings (such as `{{ value }}` or `[textContent]`), the template engine expects the browser to render the content safely. Under Server-Side Rendering (SSR), `domino` is configured with scripting enabled, meaning `<noscript>` is treated as a raw-text element.\n\nHowever, `domino`'s serializer completely omitted `<noscript>` from the list of raw-text elements requiring closing-tag escaping during DOM serialization. As a result, any occurrence of `</noscript>` in the bound dynamic text was **never escaped under any circumstances**.\n\nThe unescaped closing tag was serialized directly into the output HTML (e.g. `<noscript></noscript><script>alert(1)</script></noscript>`). When parsed by a browser, it closes the `<noscript>` block early, allowing the injected `<script>` block to execute in the user's browser context, causing same-origin Cross-Site Scripting (XSS).\n\n### Impact\n\nThis vulnerability allows an attacker to perform same-origin Cross-Site Scripting (XSS) attacks against any user visiting an SSR-rendered page that binds user-controlled data inside a `<noscript>` element. This can lead to session hijacking, credentials theft, unauthorized actions on behalf of users, and defacement.\n\n### Patched Versions\n\n- 22.0.0-rc.2\n- 21.2.16\n- 20.3.24\n- 19.2.25\n\n### Workarounds\n\nIf you cannot immediately update your dependencies, you can:\n\n- Avoid binding user-controlled values inside `<noscript>` elements.\n- Sanitize any user input placed inside `<noscript>` to explicitly strip closing `</noscript>` tags before passing it to the template.","published":"2026-06-22T15:38:28.166Z","modified":"2026-08-12T03:51:40.326947461Z","cvss":null,"epss":{"score":0.00412,"percentile":0.34297,"asOf":"2026-09-01"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@angular/platform-server","fixedVersion":"22.0.0-rc.2"},{"ecosystem":"npm","name":"@angular/platform-server","fixedVersion":"21.2.16"},{"ecosystem":"npm","name":"@angular/platform-server","fixedVersion":"20.3.24"},{"ecosystem":"npm","name":"@angular/platform-server","fixedVersion":"19.2.25"},{"ecosystem":"npm","name":"@angular/platform-server","fixedVersion":null}],"fix":{"url":"https://github.com/angular/domino/pull/29","label":"angular/domino#29"},"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50556.json"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-50556"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50556.json"},{"type":"ADVISORY","url":"https://github.com/angular/angular/security/advisories/GHSA-gxx4-3xcv-f8qx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50556"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2491459"},{"type":"REPORT","url":"https://github.com/angular/angular/issues/68903"},{"type":"FIX","url":"https://github.com/angular/domino/pull/29"},{"type":"PACKAGE","url":"https://github.com/angular/angular"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:40.326947461Z"}}