# pallets__flask-4992
# Loki Mode Multi-Agent Patch
# Attempts: 1

Based on the issue description and standard Flask codebase knowledge, I'll generate the patch. The `from_file` method in Flask's `Config` class typically opens files in text mode. The fix needs to add a `text` parameter (defaulting to `True` for backward compatibility) that controls whether to open the file in text mode (`"r"`) or binary mode (`"rb"`).

Here's the patch:

```
--- a/src/flask/config.py
+++ b/src/flask/config.py
@@ -3,6 +3,7 @@ from __future__ import annotations
 import json
 import os
 import typing as t
+from typing import IO
 
 from werkzeug.utils import import_string
 
@@ -230,6 +231,7 @@ class Config(dict):
         filename: str,
         load: t.Callable[[t.IO[t.Any]], t.Mapping],
         silent: bool = False,
+        text: bool = True,
     ) -> bool:
         """Update the values in the config from a file that is loaded
         using the ``load`` parameter. The loaded data is passed to the
@@ -248,6 +250,8 @@ class Config(dict):
         :param silent: Ignore the file if it doesn't exist.
         :type silent: bool
         :return: ``True`` if the file was loaded successfully.
+        :param text: Open the file in text mode. Defaults to ``True``.
+            Set to ``False`` for binary loaders like ``tomllib.load``.
 
         .. versionadded:: 2.0
         """
@@ -258,7 +262,8 @@ class Config(dict):
                 return False
             raise
 
-        with open(filename) as f:
+        mode = "r" if text else "rb"
+        with open(filename, mode) as f:
             obj = load(f)
 
         return self.from_mapping(obj)
```