fix: disable chroma server-side embedding functions

src/backend/base/langflow/api/utils/kb_helpers.py

@@ -37,6 +37,7 @@ from lfx.base.knowledge_bases.ingestion_sources import (
     KBIngestionSource,
 )
 from lfx.base.knowledge_bases.ingestion_sources.base import IngestionItemStatus, IngestionRunStatus
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.components.models_and_agents.embedding_model import EmbeddingModelComponent
 from lfx.log import logger
 
@@ -192,7 +193,7 @@ class KBStorageHelper:
             has_data = any((kb_path / m).exists() for m in ["chroma", "chroma.sqlite3", "index"])
             if has_data:
                 client = KBStorageHelper.get_fresh_chroma_client(kb_path)
-                chroma = Chroma(client=client, collection_name=kb_name)
+                chroma = Chroma(client=client, collection_name=kb_name, **chroma_langchain_collection_kwargs())
                 with contextlib.suppress(Exception):
                     chroma.delete_collection()
                 chroma = None
@@ -419,7 +420,7 @@ class KBAnalysisHelper:
         try:
             if created_locally:
                 client = KBStorageHelper.get_fresh_chroma_client(kb_path)
-                chroma = Chroma(client=client, collection_name=kb_path.name)
+                chroma = Chroma(client=client, collection_name=kb_path.name, **chroma_langchain_collection_kwargs())
 
             if chroma is None:
                 return

src/backend/base/langflow/api/v1/knowledge_bases.py

@@ -21,6 +21,7 @@ from lfx.base.knowledge_bases.ingestion_sources import (
     get_source_class,
     registered_sources,
 )
+from lfx.base.vectorstores.chroma_security import chroma_client_create_collection_kwargs
 from lfx.log import logger
 from pydantic import BaseModel, Field
 
@@ -588,7 +589,7 @@ async def create_knowledge_base(
         # This ensures files exist for read operations and avoids 'readonly' errors later
         try:
             client = KBStorageHelper.get_fresh_chroma_client(kb_path)
-            client.create_collection(name=kb_name)
+            client.create_collection(name=kb_name, **chroma_client_create_collection_kwargs())
         except (OSError, ValueError, chromadb.errors.ChromaError) as e:
             logger.warning("Initial Chroma setup for %s failed: %s", kb_name, e)
         finally:

src/backend/base/langflow/services/memory_base/ingestion.py

@@ -13,6 +13,7 @@ from typing import TYPE_CHECKING
 
 import chromadb.errors
 from langchain_chroma import Chroma
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.log.logger import logger
 from sqlmodel import col, func, select
 
@@ -431,7 +432,12 @@ async def _delete_chunks_for_session(
 
     client = KBStorageHelper.get_fresh_chroma_client(kb_path)
     try:
-        chroma = Chroma(client=client, embedding_function=embeddings, collection_name=kb_name)
+        chroma = Chroma(
+            client=client,
+            embedding_function=embeddings,
+            collection_name=kb_name,
+            **chroma_langchain_collection_kwargs(),
+        )
         await chroma.adelete(where={"session_id": {"$eq": session_id}})
         # Refresh on-disk metrics so the UI reflects the post-purge state.
         try:

src/backend/base/langflow/services/memory_base/kb_path_helpers.py

@@ -13,6 +13,7 @@ import uuid
 from datetime import datetime, timezone
 from typing import TYPE_CHECKING
 
+from lfx.base.vectorstores.chroma_security import chroma_client_create_collection_kwargs
 from lfx.log.logger import logger
 from sqlmodel import select
 
@@ -108,7 +109,7 @@ async def initialize_kb(
     # Initialize Chroma collection so the directory is non-empty and readable
     try:
         client = KBStorageHelper.get_fresh_chroma_client(kb_path)
-        client.create_collection(name=kb_name)
+        client.create_collection(name=kb_name, **chroma_client_create_collection_kwargs())
     except (OSError, ValueError, chromadb.errors.ChromaError) as exc:
         await logger.awarning("Initial Chroma setup for %s failed: %s", kb_name, exc)
     finally:

src/backend/base/langflow/services/memory_base/task.py

@@ -29,6 +29,7 @@ from datetime import datetime, timezone
 from typing import TYPE_CHECKING
 
 from langchain_chroma import Chroma
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.log.logger import logger
 from sqlalchemy import text
 from sqlmodel import Session, col, select
@@ -386,7 +387,12 @@ async def ingest_memory_task(*, request: IngestionRequest) -> dict:
             client = KBStorageHelper.get_fresh_chroma_client(kb_path)
             written = 0
             try:
-                chroma = Chroma(client=client, embedding_function=embeddings, collection_name=kb_name)
+                chroma = Chroma(
+                    client=client,
+                    embedding_function=embeddings,
+                    collection_name=kb_name,
+                    **chroma_langchain_collection_kwargs(),
+                )
 
                 written = await KBIngestionHelper.write_documents_to_chroma(
                     documents=documents,

src/backend/tests/unit/base/knowledge_bases/test_chroma_backend.py

@@ -318,11 +318,18 @@ class TestChromaCloudMode:
         with (
             patch("chromadb.CloudClient", return_value=mock_client) as mock_cloud,
             patch("chromadb.PersistentClient") as mock_local,
+            patch("lfx.base.knowledge_bases.backends.chroma.Chroma", return_value=MagicMock()) as mock_chroma,
         ):
             bk._build_vector_store()
 
         mock_cloud.assert_called_once()
         mock_local.assert_not_called()
+        mock_chroma.assert_called_once_with(
+            client=mock_client,
+            collection_name="cloud_test_kb",
+            embedding_function=bk.embedding_function,
+            collection_configuration={"embedding_function": None},
+        )
 
     def test_get_cloud_client_passes_optional_host_port(self, tmp_path: Path):
         from unittest.mock import patch

src/backend/tests/unit/components/vectorstores/test_chroma_vector_store_component.py

@@ -3,6 +3,10 @@ from typing import Any
 from unittest.mock import MagicMock, patch
 
 import pytest
+from lfx.base.vectorstores.chroma_security import (
+    chroma_client_create_collection_kwargs,
+    chroma_langchain_collection_kwargs,
+)
 from lfx.components.chroma import ChromaVectorStoreComponent
 from lfx.schema.data import Data
 
@@ -37,9 +41,29 @@ def test_remote_chroma_server_uses_http_client() -> None:
         client=mock_client,
         embedding_function=None,
         collection_name="remote_collection",
+        collection_configuration={"embedding_function": None},
     )
 
 
+def test_chroma_collection_security_kwargs_disable_server_side_embedding_functions() -> None:
+    assert chroma_langchain_collection_kwargs() == {
+        "collection_configuration": {"embedding_function": None},
+    }
+    assert chroma_client_create_collection_kwargs() == {
+        "configuration": {"embedding_function": None},
+        "embedding_function": None,
+    }
+
+
+def test_chroma_collection_security_kwargs_are_fresh_dicts() -> None:
+    first = chroma_langchain_collection_kwargs()
+    first["collection_configuration"]["embedding_function"] = "unsafe"
+
+    assert chroma_langchain_collection_kwargs() == {
+        "collection_configuration": {"embedding_function": None},
+    }
+
+
 @pytest.mark.api_key_required
 class TestChromaVectorStoreComponent(ComponentTestBaseWithoutClient):
     @pytest.fixture

src/backend/tests/unit/test_knowledge_bases_api.py

@@ -223,6 +223,11 @@ class TestKnowledgeBaseAPI:
         assert data["name"] == "New KB"
         assert data["backend_type"] == "opensearch"
         assert data["backend_config"] == {"index_name": "new_kb_index"}
+        mock_fresh_client.return_value.create_collection.assert_called_once_with(
+            name=kb_name,
+            configuration={"embedding_function": None},
+            embedding_function=None,
+        )
         record = await knowledge_base_service.get_by_user_and_name(active_user.id, kb_name)
         assert record is not None
         assert record.model_selection == model_selection

src/lfx/src/lfx/base/knowledge_bases/backends/chroma.py

@@ -36,6 +36,7 @@ from lfx.base.knowledge_bases.backends.base import (
     IngestedDocument,
     TestConnectionResult,
 )
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.log.logger import logger
 
 if TYPE_CHECKING:
@@ -110,6 +111,7 @@ class ChromaLocalBackend(BaseVectorStoreBackend):
             client=self._client,
             collection_name=self.kb_name,
             embedding_function=self.embedding_function,
+            **chroma_langchain_collection_kwargs(),
         )
 
     # ---- overrides --------------------------------------------------------
@@ -304,6 +306,7 @@ class ChromaCloudBackend(BaseVectorStoreBackend):
             client=self._client,
             collection_name=self.kb_name,
             embedding_function=self.embedding_function,
+            **chroma_langchain_collection_kwargs(),
         )
 
     # ---- overrides --------------------------------------------------------

src/lfx/src/lfx/base/vectorstores/chroma_security.py

@@ -0,0 +1,28 @@
+"""Safe defaults for Langflow-created Chroma collections.
+
+Chroma collection configuration can persist server-side embedding functions.
+Some embedding functions accept model-loading kwargs such as trust_remote_code.
+Langflow embeds client-side, so built-in collection creation should not register
+server-side embedding code.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+
+def chroma_langchain_collection_kwargs() -> dict[str, Any]:
+    """Return LangChain Chroma kwargs that disable Chroma server-side embedding code."""
+    return {"collection_configuration": _chroma_collection_configuration_without_embedding_function()}
+
+
+def chroma_client_create_collection_kwargs() -> dict[str, Any]:
+    """Return chromadb client kwargs that create collections without server-side embedding code."""
+    return {
+        "configuration": _chroma_collection_configuration_without_embedding_function(),
+        "embedding_function": None,
+    }
+
+
+def _chroma_collection_configuration_without_embedding_function() -> dict[str, Any]:
+    return {"embedding_function": None}

src/lfx/src/lfx/components/chroma/chroma.py

@@ -4,6 +4,7 @@ from typing import TYPE_CHECKING
 from langchain_chroma import Chroma
 from typing_extensions import override
 
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.base.vectorstores.model import LCVectorStoreComponent, check_cached_vector_store
 from lfx.base.vectorstores.utils import chroma_collection_to_data
 from lfx.inputs.inputs import BoolInput, DropdownInput, HandleInput, IntInput, StrInput
@@ -119,6 +120,7 @@ class ChromaVectorStoreComponent(LCVectorStoreComponent):
                 client=client,
                 embedding_function=self.embedding,
                 collection_name=self.collection_name,
+                **chroma_langchain_collection_kwargs(),
             )
         except Exception as e:
             if isinstance(e, ChromaError):

src/lfx/src/lfx/components/files_and_knowledge/knowledge.py

@@ -39,6 +39,7 @@ from lfx.base.knowledge_bases.ingestion_sources.base import (
 from lfx.base.knowledge_bases.ingestion_sources.flow_component import FlowComponentSource
 from lfx.base.knowledge_bases.knowledge_base_utils import get_knowledge_bases
 from lfx.base.models.unified_models import get_embedding_model_options, get_embeddings
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.components.files_and_knowledge._kb_paths import (
     get_knowledge_bases_root_path as _get_knowledge_bases_root_path,
 )
@@ -1030,6 +1031,7 @@ class KnowledgeComponent(Component):
             chroma = Chroma(
                 persist_directory=str(kb_path),
                 collection_name=self.knowledge_base,
+                **chroma_langchain_collection_kwargs(),
             )
 
             all_docs = chroma.get()

src/lfx/src/lfx/components/files_and_knowledge/memory_retrieval.py

@@ -20,6 +20,7 @@ from langflow.services.database.models.user.crud import get_user_by_id
 from langflow.services.memory_base.kb_path_helpers import hash_session_id, validate_kb_path
 from sqlmodel import select
 
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.components.files_and_knowledge._kb_paths import (
     get_knowledge_bases_root_path,
     load_kb_metadata,
@@ -234,6 +235,7 @@ class MemoryBaseComponent(Component):
             persist_directory=str(kb_path),
             embedding_function=embedding_function,
             collection_name=kb_name,
+            **chroma_langchain_collection_kwargs(),
         )
 
     def _format_results(self, results: list[tuple]) -> DataFrame:

src/lfx/src/lfx/components/vectorstores/local_db.py

@@ -4,6 +4,7 @@ from pathlib import Path
 from langchain_chroma import Chroma
 from typing_extensions import override
 
+from lfx.base.vectorstores.chroma_security import chroma_langchain_collection_kwargs
 from lfx.base.vectorstores.model import LCVectorStoreComponent, check_cached_vector_store
 from lfx.base.vectorstores.utils import chroma_collection_to_data
 from lfx.inputs.inputs import MultilineInput
@@ -226,6 +227,7 @@ class LocalDBComponent(LCVectorStoreComponent):
             client=None,
             embedding_function=self.embedding,
             collection_name=self.collection_name,
+            **chroma_langchain_collection_kwargs(),
         )
 
         self._add_documents_to_vector_store(chroma)