CVE-2026-50556 Angular: Missing `<noscript>` Raw-Text Serialization Escaping leads to Cross-Site Scripting (XSS) in Angular SSR
An XSS vulnerability in Angular SSR allows attackers to execute arbitrary scripts by injecting unescaped closing tags into noscript elements.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-50556?
CVE-2026-50556 is a high-severity cross-site scripting vulnerability in angular, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-50556?
10 open source packages ship an affected version, including @angular/platform-server. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@angular/platform-server npm | All versions to 18.2.14 | None |
@angular/platform-server npm | All versions to 18.2.14 | None |
@angular/platform-server npm | From 19.0.0-next.0 | 19.2.25 |
@angular/platform-server npm | From 19.0.0-next.0 | 19.2.25 |
@angular/platform-server npm | From 20.0.0-next.0 | 20.3.24 |
@angular/platform-server npm | From 20.0.0-next.0 | 20.3.24 |
4 more packages
@angular/platform-server npm | From 21.0.0-next.0 | 21.2.16 |
@angular/platform-server npm | From 21.0.0-next.0 | 21.2.16 |
@angular/platform-server npm | From 22.0.0-next.0 | 22.0.0-rc.2 |
@angular/platform-server npm | From 22.0.0-next.0 | 22.0.0-rc.2 |
Products include Angular Angular.
How do I fix CVE-2026-50556?
Upgrade @angular/platform-server to a fixed version for your release line: 19.2.25, 20.3.24, 21.2.16 or 22.0.0-rc.2.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-50556 being exploited?
There is no known exploitation of CVE-2026-50556 in the wild and no public exploit code.
Other vulnerabilities in angular
- CVE-2026-68945 Angular: Cache-Key Ambiguity in HttpTransferCache Leading to Cross-Request Response Reuse and State Poisoning
- CVE-2026-46417 Angular: SSRF via Hostname Hijacking in @angular/platform-server
- CVE-2026-50168 Angular: URL Parser Differential in @angular/platform-server leading to SSRF Allowlist Bypass
- CVE-2026-54266 Angular: Weak 32-Bit Cache Key Hashing in `HttpTransferCache` Leading to Cross-Request Data Leakage and State Poisoning
- CVE-2026-41423 Angular: SSRF via protocol-relative and backslash URLs in Angular Platform-Server
Sources
Also known as DEBIAN-CVE-2026-50556, GHSA-gxx4-3xcv-f8qx, UBUNTU-CVE-2026-50556.