From 3ac9ba4b503e93d36de6ee3a28e370bceff88bd6 Mon Sep 17 00:00:00 2001
From: Hrushikesh Yadav <136978914+HrushiYadav@users.noreply.github.com>
Date: Tue, 4 Aug 2026 15:16:24 +0530
Subject: [PATCH] fix(upstash): escape quotes in filter values and validate
 filter types (#5981)

---
 mem0/vector_stores/upstash_vector.py       | 45 ++++++++++++++----
 tests/vector_stores/test_upstash_vector.py | 53 +++++++++++++++++++++-
 2 files changed, 89 insertions(+), 9 deletions(-)

diff --git a/mem0/vector_stores/upstash_vector.py b/mem0/vector_stores/upstash_vector.py
index 49c2bda79..62e7f108d 100644
--- a/mem0/vector_stores/upstash_vector.py
+++ b/mem0/vector_stores/upstash_vector.py
@@ -1,5 +1,6 @@
 import logging
-from typing import Dict, List, Optional
+import re
+from typing import Any, Dict, List, Optional
 
 from pydantic import BaseModel
 
@@ -13,6 +14,23 @@ except ImportError:
 
 logger = logging.getLogger(__name__)
 
+_SAFE_FILTER_KEY = re.compile(r"[a-zA-Z_][a-zA-Z0-9_]*\Z")
+
+
+def _validate_filter(key: str, value: Any) -> None:
+    if not isinstance(key, str) or not _SAFE_FILTER_KEY.fullmatch(key):
+        raise ValueError(f"Invalid filter key: {key!r}")
+    if not isinstance(value, (str, int, float, bool)):
+        raise ValueError(
+            f"Filter value for {key!r} must be str, int, float, or bool, "
+            f"got {type(value).__name__}"
+        )
+    if isinstance(value, str) and ('"' in value or "\\" in value):
+        raise ValueError(
+            f"Filter value for {key!r} contains prohibited characters "
+            f"(double quote or backslash): {value!r}"
+        )
+
 
 class OutputData(BaseModel):
     id: Optional[str]  # memory id
@@ -92,7 +110,9 @@ class UpstashVector(VectorStoreBase):
         )
 
     def _stringify(self, x):
-        return f'"{x}"' if isinstance(x, str) else x
+        if isinstance(x, str):
+            return f'"{x}"'
+        return x
 
     def search(
         self,
@@ -113,6 +133,9 @@ class UpstashVector(VectorStoreBase):
             List[OutputData]: Search results.
         """
 
+        if filters:
+            for k, v in filters.items():
+                _validate_filter(k, v)
         filters_str = " AND ".join([f"{k} = {self._stringify(v)}" for k, v in filters.items()]) if filters else None
 
         response = []
@@ -160,13 +183,16 @@ class UpstashVector(VectorStoreBase):
         Returns:
             List[OutputData]: Search results, or None if sparse/BM25 search is not supported.
         """
-        try:
-            filters_str = (
-                " AND ".join([f"{k} = {self._stringify(v)}" for k, v in filters.items()])
-                if filters
-                else None
-            )
+        if filters:
+            for k, v in filters.items():
+                _validate_filter(k, v)
+        filters_str = (
+            " AND ".join([f"{k} = {self._stringify(v)}" for k, v in filters.items()])
+            if filters
+            else None
+        )
 
+        try:
             response = self.client.query(
                 data=query,
                 top_k=top_k,
@@ -252,6 +278,9 @@ class UpstashVector(VectorStoreBase):
         Returns:
             List[OutputData]: Search results.
         """
+        if filters:
+            for k, v in filters.items():
+                _validate_filter(k, v)
         filters_str = " AND ".join([f"{k} = {self._stringify(v)}" for k, v in filters.items()]) if filters else None
 
         info = self.client.info()
diff --git a/tests/vector_stores/test_upstash_vector.py b/tests/vector_stores/test_upstash_vector.py
index 5628028c7..b825cf80b 100644
--- a/tests/vector_stores/test_upstash_vector.py
+++ b/tests/vector_stores/test_upstash_vector.py
@@ -5,7 +5,7 @@ from unittest.mock import MagicMock, call, patch
 import pytest
 
 from mem0.configs.vector_stores.upstash_vector import UpstashVectorConfig
-from mem0.vector_stores.upstash_vector import UpstashVector
+from mem0.vector_stores.upstash_vector import UpstashVector, _validate_filter
 
 
 @dataclass
@@ -228,6 +228,57 @@ def test_update_vector_with_embeddings(upstash_instance_with_embeddings):
     )
 
 
+def test_filter_rejects_dict_value():
+    with pytest.raises(ValueError):
+        _validate_filter("user_id", {"$ne": ""})
+
+
+def test_filter_rejects_list_value():
+    with pytest.raises(ValueError):
+        _validate_filter("user_id", ["alice", "bob"])
+
+
+def test_filter_rejects_invalid_key():
+    with pytest.raises(ValueError):
+        _validate_filter("user_id; DROP", "alice")
+
+
+def test_filter_accepts_scalars():
+    _validate_filter("user_id", "alice")
+    _validate_filter("count", 42)
+    _validate_filter("score", 0.95)
+    _validate_filter("active", True)
+
+
+def test_filter_rejects_double_quote_in_value():
+    with pytest.raises(ValueError, match="prohibited characters"):
+        _validate_filter("user_id", 'alice" OR 1=1 --')
+
+
+def test_filter_rejects_backslash_in_value():
+    with pytest.raises(ValueError, match="prohibited characters"):
+        _validate_filter("user_id", "alice\\bob")
+
+
+def test_search_rejects_dict_filter(upstash_instance):
+    with pytest.raises(ValueError):
+        upstash_instance.search(
+            query="test", vectors=[[0.1]], filters={"user_id": {"$ne": ""}}
+        )
+
+
+def test_keyword_search_raises_on_invalid_filter(upstash_instance):
+    with pytest.raises(ValueError):
+        upstash_instance.keyword_search(
+            query="test", filters={"user_id": 'alice" OR 1=1'}
+        )
+
+
+def test_filter_rejects_key_with_trailing_newline():
+    with pytest.raises(ValueError, match="Invalid filter key"):
+        _validate_filter("user_id\n", "alice")
+
+
 def test_insert_vectors_with_embeddings_missing_data(upstash_instance_with_embeddings):
     vectors = [[0.1, 0.2, 0.3]]
     payloads = [{"name": "vector1"}]  # Missing data field