diff --git a/libs/checkpoint/langgraph/checkpoint/serde/jsonplus.py b/libs/checkpoint/langgraph/checkpoint/serde/jsonplus.py
index aa06ab7fc..995fb09dc 100644
--- a/libs/checkpoint/langgraph/checkpoint/serde/jsonplus.py
+++ b/libs/checkpoint/langgraph/checkpoint/serde/jsonplus.py
@@ -68,6 +68,8 @@ SAFE_MSGPACK_TYPES: frozenset[tuple[str, ...]] = frozenset(
         ("pathlib._local", "Path"),
         ("pathlib._local", "PosixPath"),
         ("pathlib._local", "WindowsPath"),
+        # regex
+        ("re", "compile"),
         # langgraph
         ("langgraph.types", "Send"),
         ("langgraph.types", "Interrupt"),
diff --git a/libs/checkpoint/tests/test_jsonplus.py b/libs/checkpoint/tests/test_jsonplus.py
index 3b2f0d072..1fde8087d 100644
--- a/libs/checkpoint/tests/test_jsonplus.py
+++ b/libs/checkpoint/tests/test_jsonplus.py
@@ -37,6 +37,10 @@ class MyPydantic(BaseModel):
     inner: InnerPydantic
 
 
+class AnotherPydantic(BaseModel):
+    foo: str
+
+
 class InnerPydanticV1(BaseModelV1):
     hello: str
 
@@ -597,3 +601,155 @@ def test_msgpack_none_blocks_unregistered(caplog: pytest.LogCaptureFixture) -> N
 
     assert "blocked" in caplog.text.lower()
     assert result is None
+
+
+def test_msgpack_allowlist_blocks_non_listed(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Allowlists should block unregistered types even if msgpack is enabled."""
+
+    serde = JsonPlusSerializer(
+        allowed_msgpack_modules=[("tests.test_jsonplus", "MyPydantic")]
+    )
+
+    obj = AnotherPydantic(foo="nope")
+
+    caplog.clear()
+    dumped = serde.dumps_typed(obj)
+    result = serde.loads_typed(dumped)
+
+    assert "blocked" in caplog.text.lower()
+    assert result is None
+
+
+def test_msgpack_strict_allows_safe_types(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Safe types should still deserialize in strict mode without warnings."""
+
+    serde = JsonPlusSerializer(allowed_msgpack_modules=None)
+    safe = uuid.uuid4()
+
+    caplog.clear()
+    dumped = serde.dumps_typed(safe)
+    result = serde.loads_typed(dumped)
+
+    assert "blocked" not in caplog.text.lower()
+    assert result == safe
+
+
+def test_msgpack_regex_safe_type(caplog: pytest.LogCaptureFixture) -> None:
+    """re.compile patterns should deserialize without warnings as a safe type."""
+
+    serde = JsonPlusSerializer(allowed_msgpack_modules=None)
+    pattern = re.compile(r"foo.*bar", re.IGNORECASE | re.DOTALL)
+
+    caplog.clear()
+    dumped = serde.dumps_typed(pattern)
+    result = serde.loads_typed(dumped)
+
+    assert "blocked" not in caplog.text.lower()
+    assert "unregistered" not in caplog.text.lower()
+    assert result.pattern == pattern.pattern
+    assert result.flags == pattern.flags
+
+
+@pytest.mark.skipif(sys.version_info >= (3, 14), reason="pydantic v1 not on 3.14+")
+def test_msgpack_pydantic_v1_allowlist(caplog: pytest.LogCaptureFixture) -> None:
+    """Pydantic v1 models in allowlist should deserialize without warnings."""
+
+    serde = JsonPlusSerializer(
+        allowed_msgpack_modules=[
+            ("tests.test_jsonplus", "MyPydanticV1"),
+            ("tests.test_jsonplus", "InnerPydanticV1"),
+        ]
+    )
+
+    obj = MyPydanticV1(foo="test", bar=42, inner=InnerPydanticV1(hello="world"))
+
+    caplog.clear()
+    dumped = serde.dumps_typed(obj)
+    result = serde.loads_typed(dumped)
+
+    assert "unregistered type" not in caplog.text.lower()
+    assert "blocked" not in caplog.text.lower()
+    assert result == obj
+
+
+def test_msgpack_dataclass_allowlist(caplog: pytest.LogCaptureFixture) -> None:
+    """Dataclasses in allowlist should deserialize without warnings."""
+
+    serde = JsonPlusSerializer(
+        allowed_msgpack_modules=[
+            ("tests.test_jsonplus", "MyDataclass"),
+            ("tests.test_jsonplus", "InnerDataclass"),
+        ]
+    )
+
+    obj = MyDataclass(foo="test", bar=42, inner=InnerDataclass(hello="world"))
+
+    caplog.clear()
+    dumped = serde.dumps_typed(obj)
+    result = serde.loads_typed(dumped)
+
+    assert "unregistered type" not in caplog.text.lower()
+    assert "blocked" not in caplog.text.lower()
+    assert result == obj
+
+
+def test_msgpack_safe_types_value_equality(caplog: pytest.LogCaptureFixture) -> None:
+    """Verify safe types are correctly restored with proper values."""
+
+    serde = JsonPlusSerializer(allowed_msgpack_modules=None)
+
+    test_cases = [
+        datetime(2024, 1, 15, 12, 30, 45, 123456),
+        date(2024, 6, 15),
+        time(14, 30, 0),
+        uuid.UUID("12345678-1234-5678-1234-567812345678"),
+        Decimal("123.456789"),
+        {1, 2, 3, 4, 5},
+        frozenset(["a", "b", "c"]),
+        deque([1, 2, 3]),
+        IPv4Address("10.0.0.1"),
+        pathlib.Path("/some/test/path"),
+        re.compile(r"\d+", re.MULTILINE),
+    ]
+
+    for obj in test_cases:
+        caplog.clear()
+        dumped = serde.dumps_typed(obj)
+        result = serde.loads_typed(dumped)
+
+        assert "blocked" not in caplog.text.lower(), f"Blocked for {type(obj)}"
+        # For regex patterns, compare pattern and flags
+        if isinstance(obj, re.Pattern):
+            assert result.pattern == obj.pattern
+            assert result.flags == obj.flags
+        else:
+            assert result == obj, f"Value mismatch for {type(obj)}: {result} != {obj}"
+
+
+def test_msgpack_nested_pydantic_serializes_as_dict(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Nested Pydantic models are serialized via model_dump() as dicts.
+
+    This means nested models don't go through the ext hook and don't need
+    to be in the allowlist - only the outer type does.
+    """
+
+    # Only allow outer type - inner is serialized as dict via model_dump()
+    serde = JsonPlusSerializer(
+        allowed_msgpack_modules=[("tests.test_jsonplus", "MyPydantic")]
+    )
+
+    obj = MyPydantic(foo="test", bar=42, inner=InnerPydantic(hello="world"))
+
+    caplog.clear()
+    dumped = serde.dumps_typed(obj)
+    result = serde.loads_typed(dumped)
+
+    # No blocking should occur - inner is serialized as dict, not ext
+    assert "blocked" not in caplog.text.lower()
+    assert result == obj
diff --git a/libs/checkpoint/tests/test_memory.py b/libs/checkpoint/tests/test_memory.py
index 7d85f4ed5..766cc1210 100644
--- a/libs/checkpoint/tests/test_memory.py
+++ b/libs/checkpoint/tests/test_memory.py
@@ -1,7 +1,9 @@
+import logging
 from typing import Any
 
 import pytest
 from langchain_core.runnables import RunnableConfig
+from pydantic import BaseModel
 
 from langgraph.checkpoint.base import (
     Checkpoint,
@@ -10,6 +12,11 @@ from langgraph.checkpoint.base import (
     empty_checkpoint,
 )
 from langgraph.checkpoint.memory import InMemorySaver
+from langgraph.checkpoint.serde.jsonplus import JsonPlusSerializer
+
+
+class MemoryPydantic(BaseModel):
+    foo: str
 
 
 class TestMemorySaver:
@@ -199,3 +206,77 @@ async def test_memory_saver() -> None:
 
     with memory_saver as sync_memory_saver:
         assert sync_memory_saver is memory_saver
+
+
+def test_memory_saver_warns_on_unregistered_msgpack(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    serde = JsonPlusSerializer()
+    memory_saver = InMemorySaver(serde=serde)
+    obj = MemoryPydantic(foo="bar")
+
+    checkpoint = empty_checkpoint()
+    checkpoint["channel_values"] = {"foo": obj}
+    checkpoint["channel_versions"] = {"foo": 1}
+
+    config: RunnableConfig = {
+        "configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
+    }
+
+    caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
+    new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
+    result = memory_saver.get_tuple(new_config)
+
+    assert result is not None
+    assert "unregistered type" in caplog.text.lower()
+    assert result.checkpoint["channel_values"]["foo"] == obj
+
+
+def test_memory_saver_allowlist_silences_warning(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    serde = JsonPlusSerializer(
+        allowed_msgpack_modules=[("tests.test_memory", "MemoryPydantic")]
+    )
+    memory_saver = InMemorySaver(serde=serde)
+    obj = MemoryPydantic(foo="bar")
+
+    checkpoint = empty_checkpoint()
+    checkpoint["channel_values"] = {"foo": obj}
+    checkpoint["channel_versions"] = {"foo": 1}
+
+    config: RunnableConfig = {
+        "configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
+    }
+
+    caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
+    new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
+    result = memory_saver.get_tuple(new_config)
+
+    assert result is not None
+    assert "unregistered type" not in caplog.text.lower()
+    assert result.checkpoint["channel_values"]["foo"] == obj
+
+
+def test_memory_saver_strict_blocks_unregistered(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    serde = JsonPlusSerializer(allowed_msgpack_modules=None)
+    memory_saver = InMemorySaver(serde=serde)
+    obj = MemoryPydantic(foo="bar")
+
+    checkpoint = empty_checkpoint()
+    checkpoint["channel_values"] = {"foo": obj}
+    checkpoint["channel_versions"] = {"foo": 1}
+
+    config: RunnableConfig = {
+        "configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
+    }
+
+    caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
+    new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
+    result = memory_saver.get_tuple(new_config)
+
+    assert result is not None
+    assert "blocked" in caplog.text.lower()
+    assert result.checkpoint["channel_values"]["foo"] is None
diff --git a/libs/cli/langgraph_cli/schemas.py b/libs/cli/langgraph_cli/schemas.py
index f190eaf94..f601f816a 100644
--- a/libs/cli/langgraph_cli/schemas.py
+++ b/libs/cli/langgraph_cli/schemas.py
@@ -165,7 +165,7 @@ class SerdeConfig(TypedDict, total=False):
     {...
         "serde": {
             "allowed_msgpack_modules": [
-                ["my_agent", "models", "MyState"],
+                ["my_agent.models", "MyState"],
             ]
         }
     }
diff --git a/libs/cli/schemas/schema.json b/libs/cli/schemas/schema.json
index 52e0c7ed6..bcd910286 100644
--- a/libs/cli/schemas/schema.json
+++ b/libs/cli/schemas/schema.json
@@ -611,7 +611,7 @@
               "type": "null"
             }
           ],
-          "description": "Optional. List of allowed python modules to de-serialize custom objects from msgpack.\n\nKnown safe types (langgraph.checkpoint.serde.jsonplus.SAFE_MSGPACK_TYPES) are always\nallowed regardless of this setting. Use this to allowlist your custom Pydantic models,\ndataclasses, and other user-defined types.\n\nIf True (default), unregistered types will log a warning but still be deserialized.\nIf None, only known safe types will be deserialized; unregistered types will be blocked.\n\n{...\n[\"my_agent\", \"models\", \"MyState\"],\n]\n}\n}\n\n{...\n}\n}\n\n"
+          "description": "Optional. List of allowed python modules to de-serialize custom objects from msgpack.\n\nKnown safe types (langgraph.checkpoint.serde.jsonplus.SAFE_MSGPACK_TYPES) are always\nallowed regardless of this setting. Use this to allowlist your custom Pydantic models,\ndataclasses, and other user-defined types.\n\nIf True (default), unregistered types will log a warning but still be deserialized.\nIf None, only known safe types will be deserialized; unregistered types will be blocked.\n\n{...\n[\"my_agent.models\", \"MyState\"],\n]\n}\n}\n\n{...\n}\n}\n\n"
         },
         "pickle_fallback": {
           "type": "boolean",
diff --git a/libs/cli/schemas/schema.v0.json b/libs/cli/schemas/schema.v0.json
index 52e0c7ed6..bcd910286 100644
--- a/libs/cli/schemas/schema.v0.json
+++ b/libs/cli/schemas/schema.v0.json
@@ -611,7 +611,7 @@
               "type": "null"
             }
           ],
-          "description": "Optional. List of allowed python modules to de-serialize custom objects from msgpack.\n\nKnown safe types (langgraph.checkpoint.serde.jsonplus.SAFE_MSGPACK_TYPES) are always\nallowed regardless of this setting. Use this to allowlist your custom Pydantic models,\ndataclasses, and other user-defined types.\n\nIf True (default), unregistered types will log a warning but still be deserialized.\nIf None, only known safe types will be deserialized; unregistered types will be blocked.\n\n{...\n[\"my_agent\", \"models\", \"MyState\"],\n]\n}\n}\n\n{...\n}\n}\n\n"
+          "description": "Optional. List of allowed python modules to de-serialize custom objects from msgpack.\n\nKnown safe types (langgraph.checkpoint.serde.jsonplus.SAFE_MSGPACK_TYPES) are always\nallowed regardless of this setting. Use this to allowlist your custom Pydantic models,\ndataclasses, and other user-defined types.\n\nIf True (default), unregistered types will log a warning but still be deserialized.\nIf None, only known safe types will be deserialized; unregistered types will be blocked.\n\n{...\n[\"my_agent.models\", \"MyState\"],\n]\n}\n}\n\n{...\n}\n}\n\n"
         },
         "pickle_fallback": {
           "type": "boolean",