diff --git a/ods/extensions/services/dashboard-api/config.py b/ods/extensions/services/dashboard-api/config.py
index b98c922fa..a49b57c12 100644
--- a/ods/extensions/services/dashboard-api/config.py
+++ b/ods/extensions/services/dashboard-api/config.py
@@ -565,8 +565,19 @@ def load_extension_catalog() -> list[dict]:
         return []
     try:
         data = json.loads(CATALOG_PATH.read_text(encoding="utf-8"))
-        return data.get("extensions", [])
-    except (json.JSONDecodeError, OSError) as e:
+        if not isinstance(data, dict):
+            raise ValueError("catalog root must be an object")
+        extensions = data.get("extensions", [])
+        if not isinstance(extensions, list):
+            raise ValueError("catalog extensions must be a list")
+        valid_extensions = [item for item in extensions if isinstance(item, dict)]
+        if len(valid_extensions) != len(extensions):
+            logger.warning(
+                "Skipped %d non-object extension catalog entries",
+                len(extensions) - len(valid_extensions),
+            )
+        return valid_extensions
+    except (json.JSONDecodeError, OSError, ValueError) as e:
         logger.warning("Failed to load extensions catalog: %s", e)
         return []
 
diff --git a/ods/extensions/services/dashboard-api/tests/test_config.py b/ods/extensions/services/dashboard-api/tests/test_config.py
index a588aee36..e1e0adfe3 100644
--- a/ods/extensions/services/dashboard-api/tests/test_config.py
+++ b/ods/extensions/services/dashboard-api/tests/test_config.py
@@ -1,5 +1,6 @@
 """Tests for config.py — manifest loading and service discovery."""
 
+import json
 import logging
 from pathlib import Path
 
@@ -80,6 +81,27 @@ def test_live_env_value_strips_one_pair_and_preserves_unmatched_quotes(monkeypat
     assert config.read_live_env_value("PAIRED") == "model-v2"
     assert config.read_live_env_value("UNMATCHED") == "model-v2'"
     assert config.read_live_env_value("REPEATED") == "'model-v2'"
+@pytest.mark.parametrize("payload", [[], {"extensions": {}}, "invalid"])
+def test_extension_catalog_rejects_invalid_payload_shape(
+    monkeypatch, tmp_path, payload
+):
+    catalog = tmp_path / "extensions-catalog.json"
+    catalog.write_text(json.dumps(payload), encoding="utf-8")
+    monkeypatch.setattr(config, "CATALOG_PATH", catalog)
+
+    assert config.load_extension_catalog() == []
+
+
+def test_extension_catalog_skips_non_object_entries(monkeypatch, tmp_path):
+    catalog = tmp_path / "extensions-catalog.json"
+    valid = {"id": "qdrant", "name": "Qdrant"}
+    catalog.write_text(
+        json.dumps({"extensions": [None, "invalid", valid]}),
+        encoding="utf-8",
+    )
+    monkeypatch.setattr(config, "CATALOG_PATH", catalog)
+
+    assert config.load_extension_catalog() == [valid]
 
 
 class TestReadManifestFile: