From 24a87b9e979abe6c2ba23421293dc0cd8cb6d65f Mon Sep 17 00:00:00 2001 From: Peter Stone Date: Sun, 5 Jul 2026 04:50:42 +0000 Subject: fix(proxy): set Host header to upstream target to satisfy loopback MCP DNS-rebinding check mcp.NewStreamableHTTPHandler rejects requests where the server is bound to loopback but the Host header is not (DNS-rebinding protection). Requests proxied through doot arrived at claudomator with Host: doot.terst.org, triggering a 403. Set req.Host = target.Host in the ReverseProxy Director so upstream services see the target host (e.g. 127.0.0.1:8484) rather than the original public hostname. --- internal/handlers/proxy.go | 1 + 1 file changed, 1 insertion(+) (limited to 'internal') diff --git a/internal/handlers/proxy.go b/internal/handlers/proxy.go index ce10a6a..ce328ef 100644 --- a/internal/handlers/proxy.go +++ b/internal/handlers/proxy.go @@ -31,6 +31,7 @@ func NewServiceProxy(targetURL, allowedOrigin, pathPrefix string) http.Handler { Director: func(req *http.Request) { req.URL.Scheme = target.Scheme req.URL.Host = target.Host + req.Host = target.Host // use upstream host so loopback services see a loopback Host header req.URL.Path = stripPrefix(req.URL.Path) if req.URL.RawPath != "" { req.URL.RawPath = stripPrefix(req.URL.RawPath) -- cgit v1.2.3