diff --git a/datamind/config.py b/datamind/config.py
index ea512e1..8f182d3 100644
--- a/datamind/config.py
+++ b/datamind/config.py
@@ -20,10 +20,11 @@
 """
 from __future__ import annotations
 
+import re
 from pathlib import Path
 from typing import Literal
 
-from pydantic import AnyUrl, BaseModel, Field, SecretStr, field_validator
+from pydantic import AnyUrl, BaseModel, ConfigDict, Field, SecretStr, field_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 # Repo root — one up from `datamind/`.
@@ -128,10 +129,21 @@ class MemoryConfig(BaseModel):
 class DataConfig(BaseModel):
     """Profile-based data layout. Paths derive from `profile`."""
 
+    model_config = ConfigDict(validate_assignment=True)
+
     profile: str = "default"
     # Root resolved at import time; tests / benchmarks can override.
     base_dir: Path = _REPO_ROOT
 
+    @field_validator("profile")
+    @classmethod
+    def _profile_name(cls, value: str) -> str:
+        if value in {".", ".."} or not re.fullmatch(r"[A-Za-z0-9_.-]+", value):
+            raise ValueError(
+                "profile must contain only letters, numbers, '.', '_' or '-'"
+            )
+        return value
+
     @property
     def data_dir(self) -> Path:
         """Per-profile raw data: data/profiles/<profile>/"""
diff --git a/datamind/tests/test_config.py b/datamind/tests/test_config.py
index 8dda7ea..dab841e 100644
--- a/datamind/tests/test_config.py
+++ b/datamind/tests/test_config.py
@@ -14,7 +14,7 @@
 import pytest
 from pydantic import ValidationError
 
-from datamind.config import Settings
+from datamind.config import DataConfig, Settings
 
 
 def test_nested_env_hydrates_required_llm(monkeypatch, tmp_path):
@@ -101,3 +101,18 @@ def test_ensure_dirs_is_idempotent(monkeypatch, tmp_path):
 
     assert (tmp_path / "data" / "profiles" / "tp").is_dir()
     assert (tmp_path / "storage" / "tp").is_dir()
+
+
+@pytest.mark.parametrize(
+    "profile",
+    ["../escape", r"..\escape", "nested/name", ".", "..", ""],
+)
+def test_profile_name_cannot_escape_profile_root(profile, tmp_path):
+    with pytest.raises(ValidationError):
+        DataConfig(base_dir=tmp_path, profile=profile)
+
+
+def test_profile_assignment_keeps_path_boundary(tmp_path):
+    config = DataConfig(base_dir=tmp_path)
+    with pytest.raises(ValidationError):
+        config.profile = "../escape"