diff --git a/tests/test_pdf_validation_typeerror_endpoint.py b/tests/test_pdf_validation_typeerror_endpoint.py
new file mode 100644
index 00000000..da00570a
--- /dev/null
+++ b/tests/test_pdf_validation_typeerror_endpoint.py
@@ -0,0 +1,37 @@
+from fastapi.testclient import TestClient
+
+from newsdom_api.config import AuthenticationMode, RuntimeProfile, RuntimeSettings
+from newsdom_api.main import create_app
+
+
+def _development_app():
+    """Create an explicit auth-disabled app for parser endpoint classification tests."""
+
+    return create_app(
+        RuntimeSettings(
+            authentication_mode=AuthenticationMode.DISABLED,
+            runtime_profile=RuntimeProfile.DEVELOPMENT,
+        ),
+        runtime_readiness_probe=lambda: True,
+    )
+
+
+def test_parse_endpoint_sanitizes_type_error_as_unsupported_media(monkeypatch):
+    """Classify a parser TypeError as invalid PDF input at the public endpoint."""
+
+    def fail_reader(_stream, *, strict):
+        assert strict is True
+        raise TypeError("malformed dictionary")
+
+    monkeypatch.setattr("newsdom_api.main.PdfReader", fail_reader)
+
+    with TestClient(_development_app()) as client:
+        response = client.post(
+            "/parse",
+            files={"file": ("fixture.pdf", b"%PDF-1.4\n%%EOF", "application/pdf")},
+        )
+
+    assert response.status_code == 415
+    assert response.json() == {"detail": "Unsupported Media Type"}
+    assert response.headers["X-Content-Type-Options"] == "nosniff"
+    assert response.headers["X-Frame-Options"] == "DENY"