diff --git a/extensions/openai/script.py b/extensions/openai/script.py
index f907cdbb..0a887de2 100644
--- a/extensions/openai/script.py
+++ b/extensions/openai/script.py
@@ -86,6 +86,20 @@ app.add_middleware(
 )
 
 
+@app.middleware("http")
+async def validate_host_header(request: Request, call_next):
+    # Be strict about only approving access to localhost by default
+    if not (shared.args.listen or shared.args.public_api):
+        host = request.headers.get("host", "").split(":")[0]
+        if host not in ["localhost", "127.0.0.1"]:
+            return JSONResponse(
+                status_code=400,
+                content={"detail": "Invalid host header"}
+            )
+
+    return await call_next(request)
+
+
 @app.options("/", dependencies=check_key)
 async def options_route():
     return JSONResponse(content="OK")
diff --git a/modules/gradio_hijack.py b/modules/gradio_hijack.py
index 2ddd983a..8e3bb0d9 100644
--- a/modules/gradio_hijack.py
+++ b/modules/gradio_hijack.py
@@ -1,5 +1,6 @@
 '''
-Copied from: https://github.com/AUTOMATIC1111/stable-diffusion-webui/pull/14184
+Most of the code here was adapted from:
+https://github.com/AUTOMATIC1111/stable-diffusion-webui/pull/14184
 '''
 
 import inspect
@@ -7,6 +8,28 @@ import warnings
 from functools import wraps
 
 import gradio as gr
+import gradio.routes
+from starlette.middleware.trustedhost import TrustedHostMiddleware
+
+from modules import shared
+
+orig_create_app = gradio.routes.App.create_app
+
+
+# Be strict about only approving access to localhost by default
+def create_app_with_trustedhost(*args, **kwargs):
+    app = orig_create_app(*args, **kwargs)
+
+    if not (shared.args.listen or shared.args.share):
+        app.add_middleware(
+            TrustedHostMiddleware,
+            allowed_hosts=["localhost", "127.0.0.1"]
+        )
+
+    return app
+
+
+gradio.routes.App.create_app = create_app_with_trustedhost
 
 
 class GradioDeprecationWarning(DeprecationWarning):