Angular Upgrade Ssr Angular Ssr Allowed Hosts V21 Security

---
id: angular.upgrade.ssr.angular-ssr-allowed-hosts-v21-security
name: Angular SSR Allowed Hosts v21 Security
description: >
  Review Angular 21 SSR allowedHosts configuration and proxy trust settings after an Angular 21 upgrade when CommonEngine, AngularAppEngine, AngularNodeAppEngine, or server-side HTTP requests depend on explicit host allowlisting.
stack:
  - Angular
  - TypeScript
category: ssr
status: stable
version: 0.10.0
owner: NgAutoPilot
triggers:
  - allowedHosts
  - SSR security
  - CommonEngine
  - trusted proxy headers
compatibility:
  angular:
    min: "21"
---

# Angular SSR Allowed Hosts v21 Security

## Purpose

Review Angular 21 SSR allowedHosts security.

## When to Use

- The app uses SSR in production.
- The app uses CommonEngine or related SSR engines.
- The app accepts proxy headers or host-based routing.

## When Not to Use

- The app does not use SSR.
- The app is still in a version hop.

## Required Inputs

- SSR entry points
- allowedHosts
- proxy header trust settings
- deployment topology

## Procedure

1. Identify SSR host validation.
2. Review proxy trust and request URL handling.
3. Validate server response behavior.

## Do

- Keep allowed hosts explicit.
- Validate trusted proxy configuration.

## Do Not

- Do not use wildcard hosts without validation.
- Do not mix this with the version hop.

## Review Checklist

- [ ] Allowed hosts are explicit.
- [ ] Proxy trust is documented.
- [ ] SSR behavior is validated.

## Expected Output

1. SSR host security summary.
2. Proxy trust summary.
3. Validation result.

## Exit Criteria

- SSR host risk is explicit.