CVE-2026-50556

Vulnerability Description

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.0-rc.2, 21.2.16, 20.3.24, and 19.2.25, a Cross-Site Scripting (XSS) vulnerability exists in @angular/platform-server's DOM emulation dependency (domino) when serializing the content of <noscript> elements. When 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. However, 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. The 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). This vulnerability is fixed in 22.0.0-rc.2, 21.2.16, 20.3.24, and 19.2.25.

CVSS Score

Affected Products

Related Weaknesses (CWE)

References

• https://github.com/angular/angular/issues/68903Issue Tracking
• https://github.com/angular/angular/security/advisories/GHSA-gxx4-3xcv-f8qxThird Party Advisory
• https://github.com/angular/domino/pull/29Issue TrackingPatch
• https://access.redhat.com/security/cve/CVE-2026-50556Third Party Advisory
• https://bugzilla.redhat.com/show_bug.cgi?id=2491459Third Party Advisory
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50556.jsonThird Party Advisory