Skip to content

Clarify trusted proxy configuration and client IP selection #8362

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
markstory merged 1 commit into from
Oct 25, 2026
Merged

Clarify trusted proxy configuration and client IP selection #8362

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
40 changes: 17 additions & 23 deletions docs/en/controllers/request-response.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -560,35 +560,29 @@ Returns the current visitor's IP address.

### Trusting Proxy Headers

If your application is behind a load balancer or running on a cloud service, you
will often get the load balancer host, port and scheme in your requests. Often
load balancers will also send `HTTP-X-Forwarded-*` headers with the original
values. The forwarded headers will not be used by CakePHP out of the box. To
have the request object use these headers set the `trustProxy` property to
`true`:
If your application is behind a load balancer or reverse proxy, forwarded
headers can contain the original host, port, scheme and client IP. CakePHP
ignores these headers by default. Define the IP addresses of proxies you
control with `setTrustedProxies()`:

```php
$this->request->trustProxy = true;

// These methods will now use the proxied headers.
$port = $this->request->port();
$host = $this->request->host();
$scheme = $this->request->scheme();
$clientIp = $this->request->clientIp();
$request->setTrustedProxies(['127.1.1.1', '127.8.1.3']);
```

Once proxies are trusted the `clientIp()` method will use the *last* IP
address in the `X-Forwarded-For` header. If your application is behind
multiple proxies, you can use `setTrustedProxies()` to define the IP addresses
of proxies in your control:
This enables `trustProxy` when the connecting address in `REMOTE_ADDR` matches
one of those proxies. On a request where `trustProxy` is false and the connecting
address is not listed, calling `setTrustedProxies()` does not enable it.

```php
$request->setTrustedProxies(['127.1.1.1', '127.8.1.3']);
```
When proxy headers are trusted, `port()`, `host()` and `scheme()` use the
forwarded headers. For `clientIp()`, CakePHP removes the configured trusted
proxies from the `X-Forwarded-For` chain and uses the rightmost remaining
address. If no trusted proxy list is configured and `trustProxy` is enabled
manually, it uses the last address in that header.

After proxies are trusted `clientIp()` will use the first IP address in the
`X-Forwarded-For` header providing it is the only value that isn't from a trusted
proxy.
> [!WARNING]
> Setting `$request->trustProxy = true` directly skips the connecting-address
> check. Only do this when your deployment ensures that requests come through
> a trusted proxy which overwrites client-supplied forwarding headers.

### Checking Accept Headers

Expand Down
Loading