diff --git a/litellm/llms/azure_ai/agents/handler.py b/litellm/llms/azure_ai/agents/handler.py
index c3cd06ab4de..9bae8abce8e 100644
--- a/litellm/llms/azure_ai/agents/handler.py
+++ b/litellm/llms/azure_ai/agents/handler.py
@@ -36,6 +36,7 @@ from typing import (
 import httpx
 
 from litellm._logging import verbose_logger
+from litellm.litellm_core_utils.url_utils import encode_url_path_segment
 from litellm.llms.azure_ai.agents.transformation import (
     AzureAIAgentsConfig,
     AzureAIAgentsError,
@@ -75,20 +76,29 @@ class AzureAIAgentsHandler:
     def _build_messages_url(
         self, api_base: str, thread_id: str, api_version: str
     ) -> str:
-        return f"{api_base}/threads/{thread_id}/messages?api-version={api_version}"
+        encoded_thread_id = encode_url_path_segment(thread_id, field_name="thread_id")
+        return (
+            f"{api_base}/threads/{encoded_thread_id}/messages?api-version={api_version}"
+        )
 
     def _build_runs_url(self, api_base: str, thread_id: str, api_version: str) -> str:
-        return f"{api_base}/threads/{thread_id}/runs?api-version={api_version}"
+        encoded_thread_id = encode_url_path_segment(thread_id, field_name="thread_id")
+        return f"{api_base}/threads/{encoded_thread_id}/runs?api-version={api_version}"
 
     def _build_run_status_url(
         self, api_base: str, thread_id: str, run_id: str, api_version: str
     ) -> str:
-        return f"{api_base}/threads/{thread_id}/runs/{run_id}?api-version={api_version}"
+        encoded_thread_id = encode_url_path_segment(thread_id, field_name="thread_id")
+        encoded_run_id = encode_url_path_segment(run_id, field_name="run_id")
+        return f"{api_base}/threads/{encoded_thread_id}/runs/{encoded_run_id}?api-version={api_version}"
 
     def _build_list_messages_url(
         self, api_base: str, thread_id: str, api_version: str
     ) -> str:
-        return f"{api_base}/threads/{thread_id}/messages?api-version={api_version}"
+        encoded_thread_id = encode_url_path_segment(thread_id, field_name="thread_id")
+        return (
+            f"{api_base}/threads/{encoded_thread_id}/messages?api-version={api_version}"
+        )
 
     def _build_create_thread_and_run_url(self, api_base: str, api_version: str) -> str:
         """URL for the create-thread-and-run endpoint (supports streaming)."""
diff --git a/litellm/llms/elevenlabs/text_to_speech/transformation.py b/litellm/llms/elevenlabs/text_to_speech/transformation.py
index 4dac2b8ba92..6a59911701b 100644
--- a/litellm/llms/elevenlabs/text_to_speech/transformation.py
+++ b/litellm/llms/elevenlabs/text_to_speech/transformation.py
@@ -11,13 +11,14 @@ import httpx
 from httpx import Headers
 
 import litellm
-from litellm.types.utils import all_litellm_params
+from litellm.litellm_core_utils.url_utils import encode_url_path_segment
 from litellm.llms.base_llm.chat.transformation import BaseLLMException
 from litellm.llms.base_llm.text_to_speech.transformation import (
     BaseTextToSpeechConfig,
     TextToSpeechRequestData,
 )
 from litellm.secret_managers.main import get_secret_str
+from litellm.types.utils import all_litellm_params
 
 from ..common_utils import ElevenLabsException
 
@@ -321,7 +322,8 @@ class ElevenLabsTextToSpeechConfig(BaseTextToSpeechConfig):
                 "ElevenLabs voice_id is required. Pass `voice` when calling `litellm.speech()`."
             )
 
-        url = f"{base_url}{self.TTS_ENDPOINT_PATH}/{voice_id}"
+        encoded_voice_id = encode_url_path_segment(voice_id, field_name="voice_id")
+        url = f"{base_url}{self.TTS_ENDPOINT_PATH}/{encoded_voice_id}"
 
         query_params = litellm_params.get(self.ELEVENLABS_QUERY_PARAMS_KEY, {})
         if query_params:
diff --git a/litellm/llms/gemini/files/transformation.py b/litellm/llms/gemini/files/transformation.py
index 401d7bb9f48..63a383ebd3d 100644
--- a/litellm/llms/gemini/files/transformation.py
+++ b/litellm/llms/gemini/files/transformation.py
@@ -12,6 +12,7 @@ import httpx
 from openai.types.file_deleted import FileDeleted
 
 from litellm._logging import verbose_logger
+from litellm.litellm_core_utils.url_utils import encode_url_path_segment
 from litellm.litellm_core_utils.prompt_templates.common_utils import extract_file_data
 from litellm.llms.base_llm.files.transformation import (
     BaseFilesConfig,
@@ -258,10 +259,14 @@ class GoogleAIStudioFilesHandler(GeminiModelInfo, BaseFilesConfig):
             normalized_file_id = file_id
 
         normalized_file_id = normalized_file_id.strip("/")
-        if not normalized_file_id.startswith("files/"):
-            normalized_file_id = f"files/{normalized_file_id}"
+        if normalized_file_id.startswith("files/"):
+            normalized_file_id = normalized_file_id.removeprefix("files/")
 
-        return normalized_file_id
+        encoded_file_id = encode_url_path_segment(
+            normalized_file_id, field_name="file_id"
+        )
+
+        return f"files/{encoded_file_id}"
 
     def transform_retrieve_file_response(
         self,
@@ -337,13 +342,8 @@ class GoogleAIStudioFilesHandler(GeminiModelInfo, BaseFilesConfig):
         if not api_key:
             raise ValueError("api_key is required")
 
-        # Extract file name from URI if full URI is provided
-        # file_id could be "files/abc123" or "https://generativelanguage.googleapis.com/v1beta/files/abc123"
-        if file_id.startswith("http"):
-            # Extract the file path from full URI
-            file_name = file_id.split("/v1beta/")[-1]
-        else:
-            file_name = file_id if file_id.startswith("files/") else f"files/{file_id}"
+        # Normalize and encode the file name before interpolating it into the URL.
+        file_name = self._normalize_gemini_file_id(file_id)
 
         # Construct the delete URL
         url = f"{api_base}/v1beta/{file_name}"
diff --git a/tests/test_litellm/llms/azure_ai/test_azure_ai_agents_handler.py b/tests/test_litellm/llms/azure_ai/test_azure_ai_agents_handler.py
new file mode 100644
index 00000000000..f65573b7ae1
--- /dev/null
+++ b/tests/test_litellm/llms/azure_ai/test_azure_ai_agents_handler.py
@@ -0,0 +1,57 @@
+import pytest
+
+from litellm.llms.azure_ai.agents.handler import AzureAIAgentsHandler
+
+
+def test_should_encode_thread_id_in_azure_ai_agent_urls():
+    handler = AzureAIAgentsHandler()
+
+    assert (
+        handler._build_messages_url(
+            "https://example.services.ai.azure.com/api/projects/proj",
+            "../../threads/other?x=1#frag",
+            "2024-05-01-preview",
+        )
+        == "https://example.services.ai.azure.com/api/projects/proj/threads/..%2F..%2Fthreads%2Fother%3Fx%3D1%23frag/messages?api-version=2024-05-01-preview"
+    )
+    assert (
+        handler._build_runs_url(
+            "https://example.services.ai.azure.com/api/projects/proj",
+            "thread/abc",
+            "2024-05-01-preview",
+        )
+        == "https://example.services.ai.azure.com/api/projects/proj/threads/thread%2Fabc/runs?api-version=2024-05-01-preview"
+    )
+
+
+def test_should_encode_thread_and_run_ids_in_azure_ai_agent_status_url():
+    handler = AzureAIAgentsHandler()
+
+    assert (
+        handler._build_run_status_url(
+            "https://example.services.ai.azure.com/api/projects/proj",
+            "thread/abc",
+            "../runs/other#frag",
+            "2024-05-01-preview",
+        )
+        == "https://example.services.ai.azure.com/api/projects/proj/threads/thread%2Fabc/runs/..%2Fruns%2Fother%23frag?api-version=2024-05-01-preview"
+    )
+
+
+def test_should_reject_dot_segments_in_azure_ai_agent_urls():
+    handler = AzureAIAgentsHandler()
+
+    with pytest.raises(ValueError, match="thread_id cannot be a dot path segment"):
+        handler._build_messages_url(
+            "https://example.services.ai.azure.com/api/projects/proj",
+            "..",
+            "2024-05-01-preview",
+        )
+
+    with pytest.raises(ValueError, match="run_id cannot be a dot path segment"):
+        handler._build_run_status_url(
+            "https://example.services.ai.azure.com/api/projects/proj",
+            "thread_123",
+            "..",
+            "2024-05-01-preview",
+        )
diff --git a/tests/test_litellm/llms/elevenlabs/test_text_to_speech_transformation.py b/tests/test_litellm/llms/elevenlabs/test_text_to_speech_transformation.py
new file mode 100644
index 00000000000..54e689dea6b
--- /dev/null
+++ b/tests/test_litellm/llms/elevenlabs/test_text_to_speech_transformation.py
@@ -0,0 +1,33 @@
+import pytest
+
+from litellm.llms.elevenlabs.text_to_speech.transformation import (
+    ElevenLabsTextToSpeechConfig,
+)
+
+
+def test_should_encode_elevenlabs_voice_id_path_segment():
+    config = ElevenLabsTextToSpeechConfig()
+
+    url = config.get_complete_url(
+        model="elevenlabs/tts",
+        api_base="https://api.elevenlabs.io",
+        litellm_params={
+            config.ELEVENLABS_VOICE_ID_KEY: "voice/../../models?x=1#frag",
+        },
+    )
+
+    assert (
+        url
+        == "https://api.elevenlabs.io/v1/text-to-speech/voice%2F..%2F..%2Fmodels%3Fx%3D1%23frag"
+    )
+
+
+def test_should_reject_dot_segment_elevenlabs_voice_id():
+    config = ElevenLabsTextToSpeechConfig()
+
+    with pytest.raises(ValueError, match="voice_id cannot be a dot path segment"):
+        config.get_complete_url(
+            model="elevenlabs/tts",
+            api_base="https://api.elevenlabs.io",
+            litellm_params={config.ELEVENLABS_VOICE_ID_KEY: ".."},
+        )
diff --git a/tests/test_litellm/llms/gemini/files/test_gemini_files_transformation.py b/tests/test_litellm/llms/gemini/files/test_gemini_files_transformation.py
index 2431c9a9c4f..d262b3b96d8 100644
--- a/tests/test_litellm/llms/gemini/files/test_gemini_files_transformation.py
+++ b/tests/test_litellm/llms/gemini/files/test_gemini_files_transformation.py
@@ -2,7 +2,6 @@
 Test Google AI Studio (Gemini) files transformation functionality
 """
 
-import os
 from unittest.mock import Mock, patch
 
 import httpx
@@ -93,6 +92,30 @@ class TestGoogleAIStudioFilesTransformation:
         assert "key=" not in url
         assert params == {}
 
+    def test_transform_retrieve_file_request_encodes_file_id_path_segment(self):
+        file_id = "files/../../models/gemini-pro?x=1#frag"
+        litellm_params = {"api_key": "test-api-key"}
+
+        url, params = self.handler.transform_retrieve_file_request(
+            file_id=file_id,
+            optional_params={},
+            litellm_params=litellm_params,
+        )
+
+        assert (
+            url
+            == "https://generativelanguage.googleapis.com/v1beta/files/..%2F..%2Fmodels%2Fgemini-pro%3Fx%3D1%23frag"
+        )
+        assert params == {}
+
+    def test_transform_retrieve_file_request_rejects_dot_path_segment(self):
+        with pytest.raises(ValueError, match="file_id cannot be a dot path segment"):
+            self.handler.transform_retrieve_file_request(
+                file_id="files/..",
+                optional_params={},
+                litellm_params={"api_key": "test-api-key"},
+            )
+
     @patch.dict("os.environ", {}, clear=True)
     @patch("litellm.llms.gemini.common_utils.get_secret_str", return_value=None)
     def test_transform_retrieve_file_request_missing_api_key(self, mock_get_secret):
@@ -322,3 +345,22 @@ class TestGoogleAIStudioFilesTransformation:
         assert file_id in url
         assert "generativelanguage.googleapis.com" in url
         assert params == {}
+
+    def test_transform_delete_file_request_encodes_file_id_path_segment(self):
+        file_id = "files/../../models/gemini-pro?x=1#frag"
+        litellm_params = {
+            "api_key": "test-api-key",
+            "api_base": "https://generativelanguage.googleapis.com",
+        }
+
+        url, params = self.handler.transform_delete_file_request(
+            file_id=file_id,
+            optional_params={},
+            litellm_params=litellm_params,
+        )
+
+        assert (
+            url
+            == "https://generativelanguage.googleapis.com/v1beta/files/..%2F..%2Fmodels%2Fgemini-pro%3Fx%3D1%23frag"
+        )
+        assert params == {}