CVE-2026-50168
Description
A flaw was found in the @angular/platform-server package of Angular. This vulnerability allows remote attackers to bypass host allowlist constraints and direct server-side outgoing requests to arbitrary external endpoints. This occurs due to a parser differential between the strict WHATWG URL parser used for allowlist validation and the lenient Domino URL parser. By sending a malformed URL with a double port structure, an attacker can cause the server to skip host validation and resolve the origin to a malicious external endpoint, leading to a Server-Side Request Forgery (SSRF) attack.
Statement
Important: A Server-Side Request Forgery (SSRF) flaw exists in Angular's @angular/platform-server package, allowing remote attackers to bypass host allowlist restrictions. This vulnerability, present in applications utilizing server-side rendering with host routing allowlists, enables the redirection of internal API requests to arbitrary external endpoints, potentially leading to information disclosure or content manipulation.
Mitigation
If updating is not immediately possible, restrict the outbound network connectivity of the server-side rendering application to only trusted backend services using network egress filtering or firewall rules to prevent connections to arbitrary external endpoints. Additionally, validate and normalize incoming request URLs and `Host` headers before they are passed to `@angular/platform-server`, rejecting malformed values that could bypass host allowlist validation. Where possible, avoid constructing the SSR request URL directly from untrusted client-supplied `Host` headers or absolute-form request URIs.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | 8.2 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | Low | Low | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
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