[http] fix: reject noncanonical static asset aliases

AGENTS.md

@@ -205,9 +205,9 @@ This file defines how coding agents should work in this repository.
   dashboard/static fallback.
 - Missing dashboard asset URLs, including raw, decoded, or repeatedly decoded
   `GET`/`HEAD` requests under `/assets/*`, dot-segment aliases that normalize
-  into `/assets`, and extension-bearing static paths, must return structured
-  JSON `404` errors instead of the dashboard HTML shell; `HEAD` responses must
-  not include a body.
+  into `/assets`, and paths with recognized static-asset extension components,
+  must return structured JSON `404` errors instead of asset bytes or the
+  dashboard HTML shell; `HEAD` responses must not include a body.
 - `HEAD` requests for GET-able dashboard/static paths such as `/` and concrete
   static assets must return the same success headers as `GET` with no body,
   while API/RPC `HEAD` requests keep the structured JSON 405/404 contract.

docs/guides/mcp.md

@@ -20,9 +20,9 @@ Exact API collection routes such as `/api/gpus` and `/api/sessions` do not
 accept query strings or path parameters unless documented; query-shaped
 collection URLs return JSON `404` responses.
 Missing packaged asset URLs, including raw, encoded, or repeatedly encoded
-`/assets/*` aliases and dot-segment aliases that normalize into the packaged
-asset directory, also return JSON `404` responses instead of the dashboard
-shell.
+`/assets/*` aliases, dot-segment aliases that normalize into the packaged asset
+directory, and paths with recognized static-asset extension components, also
+return JSON `404` responses instead of asset bytes or the dashboard shell.
 
 ## Start service
 

src/keep_gpu/mcp/server.py

@@ -79,6 +79,9 @@
 STATIC_DIR = Path(__file__).resolve().parent / "static"
 MAX_JSON_BODY_BYTES = 1_000_000
 ROUTE_PATH_DECODE_MAX_PASSES = 16
+STATIC_ASSET_SUFFIXES = frozenset(
+    {".css", ".html", ".ico", ".js", ".json", ".map", ".png", ".svg"}
+)
 MCP_PROTOCOL_VERSION = "2025-06-18"
 JSONRPC_PARSE_ERROR = -32700
 JSONRPC_INVALID_REQUEST = -32600
@@ -1348,6 +1351,17 @@ def _serve_static(self, request_path: str, write_body: bool = True) -> None:
             relative = request_path.lstrip("/")
 
         decoded_relative = unquote(relative)
+        decoded_components = [
+            component for component in decoded_relative.split("/") if component
+        ]
+        has_dot_segment = any(
+            component in (".", "..") for component in decoded_components
+        )
+        has_extension_component = any(
+            Path(component).suffix.lower() in STATIC_ASSET_SUFFIXES
+            for component in decoded_components
+            if component not in (".", "..")
+        )
         requested = (STATIC_DIR / decoded_relative).resolve()
         static_root = STATIC_DIR.resolve()
         is_asset_route_alias = any(
@@ -1374,13 +1388,28 @@ def _serve_static(self, request_path: str, write_body: bool = True) -> None:
         is_asset_prefix_request = (
             decoded_relative == "assets" or decoded_relative.startswith("assets/")
         )
+        is_canonical_asset_request = (
+            is_asset_prefix_request
+            and (relative == "assets" or relative.startswith("assets/"))
+            and not has_dot_segment
+        )
+        is_noncanonical_resolved_asset = (
+            is_resolved_asset_request
+            and is_asset_route_alias
+            and not is_canonical_asset_request
+        )
+        if is_noncanonical_resolved_asset:
+            self._json_response(
+                404,
+                {"error": {"message": "Static asset not found"}},
+                write_body=write_body,
+            )
+            return
         is_asset_request = (
             is_asset_prefix_request
             or is_resolved_asset_request
             or is_asset_route_alias
-            or (
-                bool(Path(decoded_relative).suffix) and decoded_relative != "index.html"
-            )
+            or (has_extension_component and decoded_relative != "index.html")
         )
         if (
             is_asset_prefix_request

tests/mcp/test_http_api.py

@@ -1342,7 +1342,32 @@ class _Server(TCPServer):
         thread.join(timeout=2)
 
 
-@pytest.mark.parametrize("path", ["/assets/missing.js", "/missing.keepgpu-test.js"])
+@pytest.mark.parametrize("path", ["/dashboard/settings", "/v1.0/dashboard"])
+def test_http_dashboard_client_routes_fall_back_to_static_index(path):
+    server = make_server()
+    httpd, thread, base = _start_http_server(server)
+
+    try:
+        status, headers, body = _request_http_response("GET", f"{base}{path}")
+    finally:
+        httpd.shutdown()
+        httpd.server_close()
+        server.shutdown()
+        thread.join(timeout=2)
+
+    assert status == 200
+    assert headers.get_content_type() == "text/html"
+    assert b"KeepGPU Control Deck" in body
+
+
+@pytest.mark.parametrize(
+    "path",
+    [
+        "/assets/missing.js",
+        "/missing.keepgpu-test.js",
+        "/missing.keepgpu-test.js/extra",
+    ],
+)
 def test_http_missing_static_asset_returns_404_not_dashboard_index(path):
     server = make_server()
     httpd, thread, base = _start_http_server(server)
@@ -1390,7 +1415,10 @@ def test_http_normalized_asset_escape_returns_404_not_dashboard_index(target):
     }
 
 
-@pytest.mark.parametrize("target", ["/foo/../assets/missing", "/foo/../assets"])
+@pytest.mark.parametrize(
+    "target",
+    ["/foo/../assets/missing", "/foo/../assets", "/foo/../assets/index.css"],
+)
 def test_http_normalized_asset_alias_returns_404_not_dashboard_index(target):
     server = make_server()
     httpd, thread, _base = _start_http_server(server)
@@ -1418,6 +1446,7 @@ def test_http_normalized_asset_alias_returns_404_not_dashboard_index(target):
         "/%252Fassets/missing",
         "/%2Fassets/index.css",
         "/%252Fassets/index.css",
+        "/assets%2Findex.css",
     ],
 )
 def test_http_encoded_leading_slash_asset_alias_returns_404_not_dashboard_index(
@@ -1442,7 +1471,14 @@ def test_http_encoded_leading_slash_asset_alias_returns_404_not_dashboard_index(
     }
 
 
-@pytest.mark.parametrize("path", ["/assets/missing.js", "/missing.keepgpu-test.js"])
+@pytest.mark.parametrize(
+    "path",
+    [
+        "/assets/missing.js",
+        "/missing.keepgpu-test.js",
+        "/missing.keepgpu-test.js/extra",
+    ],
+)
 def test_http_head_missing_static_asset_returns_json_404_without_body(path):
     server = make_server()
     httpd, thread, base = _start_http_server(server)
@@ -1485,7 +1521,10 @@ def test_http_head_normalized_asset_escape_returns_404_without_body(target):
     assert body == b""
 
 
-@pytest.mark.parametrize("target", ["/foo/../assets/missing", "/foo/../assets"])
+@pytest.mark.parametrize(
+    "target",
+    ["/foo/../assets/missing", "/foo/../assets", "/foo/../assets/index.css"],
+)
 def test_http_head_normalized_asset_alias_returns_404_without_body(target):
     server = make_server()
     httpd, thread, _base = _start_http_server(server)
@@ -1510,6 +1549,7 @@ def test_http_head_normalized_asset_alias_returns_404_without_body(target):
         "/%252Fassets/missing",
         "/%2Fassets/index.css",
         "/%252Fassets/index.css",
+        "/assets%2Findex.css",
     ],
 )
 def test_http_head_encoded_leading_slash_asset_alias_returns_404_without_body(