diff --git a/litellm/litellm_core_utils/audio_utils/utils.py b/litellm/litellm_core_utils/audio_utils/utils.py
index 2141df18738..82f5c27f836 100644
--- a/litellm/litellm_core_utils/audio_utils/utils.py
+++ b/litellm/litellm_core_utils/audio_utils/utils.py
@@ -53,8 +53,19 @@ def process_audio_file(audio_file: FileTypes) -> ProcessedAudioFile:
         # Raw bytes
         filename = "audio.wav"
         file_content = bytes(audio_file)
-    elif isinstance(audio_file, (str, os.PathLike)):
-        # File path or PathLike
+    elif isinstance(audio_file, str):
+        # Bare strings are rejected — see extract_file_data for the same
+        # rationale: in a proxy request handler the string is
+        # attacker-controlled, and opening it as a path is an arbitrary
+        # file read.
+        raise ValueError(
+            "process_audio_file does not accept bare str inputs. Pass bytes, "
+            "an open file handle, a (filename, content) tuple, or a "
+            "pathlib.Path."
+        )
+    elif isinstance(audio_file, os.PathLike):
+        # File path or PathLike — PathLike is a Python-level type that
+        # HTTP form values can't fabricate.
         file_path = str(audio_file)
         with open(file_path, "rb") as f:
             file_content = f.read()
@@ -66,8 +77,14 @@ def process_audio_file(audio_file: FileTypes) -> ProcessedAudioFile:
             content = audio_file[1]
             if isinstance(content, (bytes, bytearray)):
                 file_content = bytes(content)
-            elif isinstance(content, (str, os.PathLike)):
-                # File path or PathLike
+            elif isinstance(content, str):
+                raise ValueError(
+                    "process_audio_file does not accept bare str tuple "
+                    "contents. Pass bytes, an open file handle, or a "
+                    "pathlib.Path."
+                )
+            elif isinstance(content, os.PathLike):
+                # PathLike: SDK convenience for local-file uploads.
                 with open(str(content), "rb") as f:
                     file_content = f.read()
             elif hasattr(content, "read"):
@@ -149,7 +166,14 @@ def get_audio_file_content_hash(file_obj: FileTypes) -> str:
     try:
         if isinstance(file_content_obj, (bytes, bytearray)):
             file_content = bytes(file_content_obj)
-        elif isinstance(file_content_obj, (str, os.PathLike)):
+        elif isinstance(file_content_obj, str):
+            # Bare strings are not treated as file paths in this helper —
+            # the cache-key path is reached from request handlers where the
+            # value is attacker-controlled. Fall back to hashing the string
+            # itself rather than opening it.
+            fallback_filename = file_content_obj
+            file_content = None
+        elif isinstance(file_content_obj, os.PathLike):
             try:
                 with open(str(file_content_obj), "rb") as f:
                     file_content = f.read()
@@ -229,8 +253,15 @@ def calculate_request_duration(file: FileTypes) -> Optional[float]:
         if isinstance(file, (bytes, bytearray)):
             # Raw bytes
             file_content = bytes(file)
-        elif isinstance(file, (str, os.PathLike)):
-            # File path
+        elif isinstance(file, str):
+            # Bare strings are rejected — see extract_file_data.
+            raise ValueError(
+                "calculate_request_duration does not accept bare str inputs. "
+                "Pass bytes, an open file handle, a (filename, content) "
+                "tuple, or a pathlib.Path."
+            )
+        elif isinstance(file, os.PathLike):
+            # File path (PathLike): SDK convenience.
             with open(str(file), "rb") as f:
                 file_content = f.read()
         elif isinstance(file, tuple):
diff --git a/litellm/litellm_core_utils/prompt_templates/common_utils.py b/litellm/litellm_core_utils/prompt_templates/common_utils.py
index b234e6c8f77..ddc6f0d116d 100644
--- a/litellm/litellm_core_utils/prompt_templates/common_utils.py
+++ b/litellm/litellm_core_utils/prompt_templates/common_utils.py
@@ -726,14 +726,25 @@ def extract_file_data(file_data: FileTypes) -> ExtractedFileData:
     else:
         file_content = file_data
     # Convert content to bytes
-    if isinstance(file_content, (str, PathLike)):
-        # If it's a path, open and read the file
-        # Extract filename from path if not already set
+    if isinstance(file_content, str):
+        # Bare string inputs are rejected: when this helper runs in a proxy
+        # request handler the string came from an attacker-controlled form
+        # field, and opening it as a path is an arbitrary file read on the
+        # proxy host. SDK callers who want to upload from a path should
+        # either pass a pathlib.Path (a PathLike instance — see the branch
+        # below) or open the file themselves and pass the handle / bytes.
+        raise ValueError(
+            "extract_file_data does not accept bare str inputs. Pass bytes, "
+            "an open file handle, a (filename, content) tuple, or a "
+            "pathlib.Path. To upload a local file from a path, call "
+            "open(path, 'rb') yourself."
+        )
+    if isinstance(file_content, PathLike):
+        # PathLike (pathlib.Path) is a Python-level type that HTTP form
+        # values can't fabricate. Treat as a local file path for SDK
+        # convenience.
         if filename is None:
-            if isinstance(file_content, PathLike):
-                filename = Path(file_content).name
-            else:
-                filename = Path(str(file_content)).name
+            filename = Path(file_content).name
         with open(file_content, "rb") as f:
             content = f.read()
     elif isinstance(file_content, io.IOBase):
diff --git a/litellm/ocr/main.py b/litellm/ocr/main.py
index 5d73ddc8972..b27082c361a 100644
--- a/litellm/ocr/main.py
+++ b/litellm/ocr/main.py
@@ -10,7 +10,6 @@ import os
 import re
 from functools import partial
 from io import IOBase
-from pathlib import Path
 from typing import Any, Coroutine, Dict, Optional, Union
 
 import httpx
@@ -376,11 +375,13 @@ def convert_file_document_to_url_document(document: Dict[str, Any]) -> Dict[str,
     with an inline base64 data URI.
 
     Accepts document dicts like:
-        {"type": "file", "file": "/path/to/document.pdf"}        # file path string
         {"type": "file", "file": Path("/path/to/doc.pdf")}       # pathlib.Path
         {"type": "file", "file": <binary file-like object>}      # file-like object (BinaryIO)
         {"type": "file", "file": b"raw bytes"}                   # raw bytes
 
+    Bare ``str`` paths are not accepted — pass a ``pathlib.Path`` or
+    ``open(path, "rb")`` instead. See the str check below for the rationale.
+
     Returns:
         {"type": "document_url", "document_url": "data:<mime>;base64,<data>"}
         or {"type": "image_url", "image_url": "data:<mime>;base64,<data>"}
@@ -389,14 +390,28 @@ def convert_file_document_to_url_document(document: Dict[str, Any]) -> Dict[str,
     if file_input is None:
         raise ValueError(
             "document with type='file' must include a 'file' field containing "
-            "a file path (str), pathlib.Path, file-like object, or bytes"
+            "a pathlib.Path, file-like object, or bytes"
         )
 
     file_bytes: bytes
     mime_type: str = "application/octet-stream"
     file_name: Optional[str] = None
 
-    if isinstance(file_input, (str, Path)):
+    if isinstance(file_input, str):
+        # Bare strings are rejected here. The OCR ``document`` accepts a
+        # ``{"type": "file", "file": <value>}`` shape, and when this helper
+        # runs in a proxy request handler ``<value>`` is attacker-controlled.
+        # Opening it as a path is an arbitrary local file read on the proxy
+        # host, which is then base64-encoded and forwarded to the OCR
+        # provider — an exfiltration primitive.
+        raise ValueError(
+            "OCR file input does not accept bare str values. Pass bytes, "
+            "a pathlib.Path, or a file-like object. To OCR a local file "
+            "from a path, call open(path, 'rb') yourself."
+        )
+    if isinstance(file_input, os.PathLike):
+        # os.PathLike (pathlib.Path and custom __fspath__ classes) is a
+        # Python-level type that HTTP form values can't fabricate.
         file_path = str(file_input)
         if not os.path.isfile(file_path):
             raise FileNotFoundError(f"File not found: {file_path}")
@@ -417,7 +432,7 @@ def convert_file_document_to_url_document(document: Dict[str, Any]) -> Dict[str,
     else:
         raise ValueError(
             f"Unsupported file input type: {type(file_input)}. "
-            "Expected str (file path), pathlib.Path, bytes, or a file-like object."
+            "Expected pathlib.Path, bytes, or a file-like object."
         )
 
     if not file_bytes:
diff --git a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
index 22d2610eecb..021a4bbd015 100644
--- a/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
+++ b/tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
@@ -367,3 +367,57 @@ def test_update_messages_with_model_file_ids_skips_non_openai_file_blocks():
 
     # Messages pass through unchanged when there is no `file` sub-dict to remap.
     assert updated == messages
+
+
+class TestExtractFileDataBareStr:
+    """``extract_file_data`` used to accept bare ``str`` values and ``open()``
+    them server-side. When the helper runs inside a proxy request handler the
+    value is attacker-controlled, so the open() call was a textbook arbitrary
+    local file read. Lock the new contract: bare ``str`` is rejected with a
+    clear migration message; ``pathlib.Path`` is still accepted for SDK
+    ergonomics because it's a Python-level type that HTTP form values can't
+    fabricate."""
+
+    def test_rejects_bare_str(self):
+        from litellm.litellm_core_utils.prompt_templates.common_utils import (
+            extract_file_data,
+        )
+
+        with pytest.raises(ValueError, match="does not accept bare str inputs"):
+            extract_file_data("/etc/passwd")
+
+    def test_accepts_pathlib_path(self):
+        import tempfile
+        from pathlib import Path
+
+        from litellm.litellm_core_utils.prompt_templates.common_utils import (
+            extract_file_data,
+        )
+
+        content = b"hello"
+        with tempfile.NamedTemporaryFile(suffix=".txt", delete=False) as f:
+            f.write(content)
+            tmp_path = Path(f.name)
+
+        try:
+            extracted = extract_file_data(tmp_path)
+            assert extracted.get("content") == content
+        finally:
+            os.unlink(str(tmp_path))
+
+    def test_accepts_bytes(self):
+        from litellm.litellm_core_utils.prompt_templates.common_utils import (
+            extract_file_data,
+        )
+
+        extracted = extract_file_data(b"raw bytes content")
+        assert extracted.get("content") == b"raw bytes content"
+
+    def test_accepts_tuple(self):
+        from litellm.litellm_core_utils.prompt_templates.common_utils import (
+            extract_file_data,
+        )
+
+        extracted = extract_file_data(("foo.txt", b"raw bytes content"))
+        assert extracted.get("filename") == "foo.txt"
+        assert extracted.get("content") == b"raw bytes content"
diff --git a/tests/test_litellm/litellm_core_utils/test_audio_utils.py b/tests/test_litellm/litellm_core_utils/test_audio_utils.py
index d9df9059d9f..b2645c8f2ce 100644
--- a/tests/test_litellm/litellm_core_utils/test_audio_utils.py
+++ b/tests/test_litellm/litellm_core_utils/test_audio_utils.py
@@ -42,8 +42,10 @@ class TestProcessAudioFile:
         assert result.filename == "audio.wav"
         assert result.content_type == "audio/wav"
 
-    def test_process_file_path_input(self):
-        """Test processing file path input"""
+    def test_process_pathlib_input(self):
+        """pathlib.Path is a Python-level type HTTP form values can't fabricate."""
+        from pathlib import Path
+
         test_content = b"test audio content"
 
         with tempfile.NamedTemporaryFile(suffix=".mp3", delete=False) as temp_file:
@@ -51,15 +53,22 @@ class TestProcessAudioFile:
             temp_file_path = temp_file.name
 
         try:
-            result = process_audio_file(temp_file_path)
+            result = process_audio_file(Path(temp_file_path))
 
             assert isinstance(result, ProcessedAudioFile)
             assert result.file_content == test_content
             assert result.filename == os.path.basename(temp_file_path)
-            assert result.content_type == "audio/mpeg"  # .mp3 should map to audio/mpeg
+            assert result.content_type == "audio/mpeg"
         finally:
             os.unlink(temp_file_path)
 
+    def test_process_bare_str_path_rejected(self):
+        """Bare str paths are rejected — when this runs in a proxy request
+        handler the value is attacker-controlled, and opening it as a path
+        is an arbitrary local file read."""
+        with pytest.raises(ValueError, match="does not accept bare str inputs"):
+            process_audio_file("/etc/passwd")
+
     def test_process_tuple_input_with_bytes(self):
         """Test processing tuple input with bytes content"""
         filename = "test.wav"
@@ -73,8 +82,10 @@ class TestProcessAudioFile:
         assert result.filename == filename
         assert result.content_type == "audio/wav"
 
-    def test_process_tuple_input_with_file_path(self):
-        """Test processing tuple input with file path content"""
+    def test_process_tuple_input_with_pathlib_content(self):
+        """Tuple input with pathlib.Path content is allowed; bare str content is not."""
+        from pathlib import Path
+
         test_content = b"test audio content"
 
         with tempfile.NamedTemporaryFile(suffix=".flac", delete=False) as temp_file:
@@ -83,7 +94,7 @@ class TestProcessAudioFile:
 
         try:
             filename = "custom_name.flac"
-            audio_tuple = (filename, temp_file_path)
+            audio_tuple = (filename, Path(temp_file_path))
 
             result = process_audio_file(audio_tuple)
 
diff --git a/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py b/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
index 977c53280a9..263fb1c6e65 100644
--- a/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
+++ b/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
@@ -1454,40 +1454,34 @@ def test_extract_file_data_with_path_object():
         os.unlink(tmp_path)
 
 
-def test_extract_file_data_with_string_path():
-    """Test that filename is correctly extracted from string paths."""
+def test_extract_file_data_with_pathlib_path():
+    """Test that filename is correctly extracted from pathlib.Path inputs.
+    Bare str paths are rejected — when this runs in a proxy request handler
+    the value is attacker-controlled and opening it as a path is an LFI."""
     import os
     import tempfile
+    from pathlib import Path
 
     from litellm.litellm_core_utils.prompt_templates.common_utils import (
         extract_file_data,
     )
 
-    # Create a temporary WAV file
     with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as tmp:
         tmp.write(b"fake wav content")
-        tmp_path = tmp.name
+        tmp_path = Path(tmp.name)
 
     try:
-        # Test with string path
         extracted = extract_file_data(tmp_path)
 
-        # Verify filename was extracted
         assert extracted["filename"] is not None
         assert extracted["filename"].endswith(".wav")
-
-        # Verify MIME type was correctly detected (can be audio/wav or audio/x-wav depending on system)
         assert extracted["content_type"] in [
             "audio/wav",
             "audio/x-wav",
         ], f"Expected 'audio/wav' or 'audio/x-wav' but got '{extracted['content_type']}'"
-
-        # Verify content was read
         assert extracted["content"] == b"fake wav content"
-
     finally:
-        # Clean up temporary file
-        os.unlink(tmp_path)
+        os.unlink(str(tmp_path))
 
 
 def test_extract_file_data_with_tuple_format():
@@ -1510,35 +1504,29 @@ def test_extract_file_data_with_tuple_format():
 
 
 def test_extract_file_data_fallback_to_octet_stream():
-    """Test that unknown file types fall back to application/octet-stream."""
+    """Unknown file types fall back to application/octet-stream."""
     import os
     import tempfile
+    from pathlib import Path
 
     from litellm.litellm_core_utils.prompt_templates.common_utils import (
         extract_file_data,
     )
 
-    # Create a temporary file with unknown extension
     with tempfile.NamedTemporaryFile(suffix=".xyz123", delete=False) as tmp:
         tmp.write(b"unknown content")
-        tmp_path = tmp.name
+        tmp_path = Path(tmp.name)
 
     try:
-        # Test with unknown file type
         extracted = extract_file_data(tmp_path)
 
-        # Verify filename was extracted
         assert extracted["filename"] is not None
         assert extracted["filename"].endswith(".xyz123")
-
-        # Verify MIME type falls back to octet-stream
         assert (
             extracted["content_type"] == "application/octet-stream"
         ), f"Expected 'application/octet-stream' for unknown type, got '{extracted['content_type']}'"
-
     finally:
-        # Clean up temporary file
-        os.unlink(tmp_path)
+        os.unlink(str(tmp_path))
 
 
 def test_convert_tool_response_with_pdf_file():
diff --git a/tests/test_litellm/ocr/test_ocr_file_input.py b/tests/test_litellm/ocr/test_ocr_file_input.py
index 4e56aa56ee6..e6216d7c580 100644
--- a/tests/test_litellm/ocr/test_ocr_file_input.py
+++ b/tests/test_litellm/ocr/test_ocr_file_input.py
@@ -60,14 +60,15 @@ class TestGetMimeType:
 
 
 class TestConvertFileDocumentToUrlDocument:
-    def test_should_convert_pdf_file_path_to_document_url(self):
-        """File path to a PDF should produce type=document_url with base64 data URI."""
+    def test_should_convert_pdf_pathlib_path_to_document_url(self):
+        """pathlib.Path to a PDF should produce type=document_url with base64 data URI.
+        Bare str paths are rejected — see test_should_reject_bare_str_path below."""
         pdf_content = b"%PDF-1.4 test content"
 
         with tempfile.NamedTemporaryFile(suffix=".pdf", delete=False) as f:
             f.write(pdf_content)
             f.flush()
-            tmp_path = f.name
+            tmp_path = Path(f.name)
 
         try:
             result = convert_file_document_to_url_document(
@@ -80,16 +81,16 @@ class TestConvertFileDocumentToUrlDocument:
             b64_data = result["document_url"].split(";base64,")[1]
             assert base64.b64decode(b64_data) == pdf_content
         finally:
-            os.unlink(tmp_path)
+            os.unlink(str(tmp_path))
 
-    def test_should_convert_image_file_path_to_image_url(self):
-        """File path to a PNG image should produce type=image_url with base64 data URI."""
+    def test_should_convert_image_pathlib_path_to_image_url(self):
+        """pathlib.Path to a PNG image should produce type=image_url with base64 data URI."""
         png_content = b"\x89PNG\r\n\x1a\n fake png content"
 
         with tempfile.NamedTemporaryFile(suffix=".png", delete=False) as f:
             f.write(png_content)
             f.flush()
-            tmp_path = f.name
+            tmp_path = Path(f.name)
 
         try:
             result = convert_file_document_to_url_document(
@@ -102,7 +103,16 @@ class TestConvertFileDocumentToUrlDocument:
             b64_data = result["image_url"].split(";base64,")[1]
             assert base64.b64decode(b64_data) == png_content
         finally:
-            os.unlink(tmp_path)
+            os.unlink(str(tmp_path))
+
+    def test_should_reject_bare_str_path(self):
+        """Bare str ``file`` values are rejected — when this runs in a proxy
+        request handler the value is attacker-controlled, and opening it as
+        a path is an arbitrary local file read on the proxy host."""
+        with pytest.raises(ValueError, match="does not accept bare str values"):
+            convert_file_document_to_url_document(
+                {"type": "file", "file": "/etc/passwd"}
+            )
 
     def test_should_convert_pathlib_path(self):
         """pathlib.Path objects should work the same as string paths."""
@@ -189,17 +199,17 @@ class TestConvertFileDocumentToUrlDocument:
         with pytest.raises(ValueError, match="must include a 'file' field"):
             convert_file_document_to_url_document({"type": "file"})
 
-    def test_should_raise_error_for_nonexistent_file_path(self):
-        """Non-existent file path should raise FileNotFoundError."""
+    def test_should_raise_error_for_nonexistent_pathlib_path(self):
+        """Non-existent pathlib.Path should raise FileNotFoundError."""
         with pytest.raises(FileNotFoundError, match="File not found"):
             convert_file_document_to_url_document(
-                {"type": "file", "file": "/nonexistent/path/to/file.pdf"}
+                {"type": "file", "file": Path("/nonexistent/path/to/file.pdf")}
             )
 
     def test_should_raise_error_for_empty_file(self):
         """Empty file should raise ValueError."""
         with tempfile.NamedTemporaryFile(suffix=".pdf", delete=False) as f:
-            tmp_path = f.name
+            tmp_path = Path(f.name)
 
         try:
             with pytest.raises(ValueError, match="File is empty"):
@@ -207,7 +217,7 @@ class TestConvertFileDocumentToUrlDocument:
                     {"type": "file", "file": tmp_path}
                 )
         finally:
-            os.unlink(tmp_path)
+            os.unlink(str(tmp_path))
 
     def test_should_raise_error_for_unsupported_type(self):
         """Unsupported file input types should raise ValueError."""
@@ -226,14 +236,14 @@ class TestConvertFileDocumentToUrlDocument:
                 }
             )
 
-    def test_should_override_mime_type_for_file_path(self):
+    def test_should_override_mime_type_for_pathlib_path(self):
         """Explicit mime_type should override auto-detection from extension."""
         content = b"some content"
 
         with tempfile.NamedTemporaryFile(suffix=".pdf", delete=False) as f:
             f.write(content)
             f.flush()
-            tmp_path = f.name
+            tmp_path = Path(f.name)
 
         try:
             result = convert_file_document_to_url_document(
@@ -243,7 +253,7 @@ class TestConvertFileDocumentToUrlDocument:
             assert result["type"] == "image_url"
             assert result["image_url"].startswith("data:image/png;base64,")
         finally:
-            os.unlink(tmp_path)
+            os.unlink(str(tmp_path))
 
 
 class TestBuildDocumentFromUpload: