Server-Side Request Forgery (SSRF) in Angular SSR

The Angular SSR is a server-rise rendering tool for Angular applications. The vulnerability is a Server-Side Request Forgery (SSRF) flaw within the URL resolution mechanism of Angular's Server-Side Rendering package (@angular/ssr) before 19.2.18, 20.3.6, and 21.0.0-next.8. The function createRequestUrl uses the native URL constructor. When an incoming request path (e.g., originalUrl or url) begins with a double forward slash (//) or backslash (\\), the URL constructor treats it as a schema-relative URL. This behavior overrides the security-intended base URL (protocol, host, and port) supplied as the second argument, instead resolving the URL against the scheme of the base URL but adopting the attacker-controlled hostname. This allows an attacker to specify an external domain in the URL path, tricking the Angular SSR environment into setting the page's virtual location (accessible via DOCUMENT or PlatformLocation tokens) to this attacker-controlled domain. Any subsequent relative HTTP requests made during the SSR process (e.g., using HttpClient.get('assets/data.json')) will be incorrectly resolved against the attacker's domain, forcing the server to communicate with an arbitrary external endpoint. This vulnerability is fixed in 19.2.18, 20.3.6, and 21.0.0-next.8.

Source published

16 Oct 2025 18:50:11 UTC

Source modified

17 Oct 2025 13:24:15 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N