diff --git a/backend/project/endpoints/courses/courses.py b/backend/project/endpoints/courses/courses.py
index 04b645ed..7145903d 100644
--- a/backend/project/endpoints/courses/courses.py
+++ b/backend/project/endpoints/courses/courses.py
@@ -47,8 +47,8 @@ def get(self, uid=None):
             # Apply filters dynamically if they are provided
             for param, value in filter_params.items():
                 if value:
-                    attribute = getattr(Course, param, None)
-                    if attribute:
+                    if param in Course.__table__.columns:
+                        attribute = getattr(Course, param)
                         base_query = base_query.filter(attribute == value)
 
             # Define the role-specific queries
diff --git a/backend/project/endpoints/projects/projects.py b/backend/project/endpoints/projects/projects.py
index e19538ad..27b603a3 100644
--- a/backend/project/endpoints/projects/projects.py
+++ b/backend/project/endpoints/projects/projects.py
@@ -54,7 +54,8 @@ def get(self, uid=None):
             filters = dict(request.args)
             conditions = []
             for key, value in filters.items():
-                conditions.append(getattr(Project, key) == value)
+                if key in Project.__table__.columns:
+                    conditions.append(getattr(Project, key) == value)
 
             # Get the projects
             projects = Project.query
diff --git a/backend/project/endpoints/submissions/submissions.py b/backend/project/endpoints/submissions/submissions.py
index b80319ab..c983b398 100644
--- a/backend/project/endpoints/submissions/submissions.py
+++ b/backend/project/endpoints/submissions/submissions.py
@@ -44,11 +44,6 @@ def get(self, uid=None) -> dict[str, any]:
         }
         filters = dict(request.args)
         try:
-            invalid_parameters = set(filters.keys()) - {"uid", "project_id"}
-            if invalid_parameters:
-                data["message"] = f"Invalid query parameter(s) {invalid_parameters}"
-                return data, 400
-
             # Check the uid query parameter
             user_id = filters.get("uid")
             if user_id and not isinstance(user_id, str):
@@ -73,7 +68,8 @@ def get(self, uid=None) -> dict[str, any]:
             # Filter the courses based on the query parameters
             conditions = []
             for key, value in filters.items():
-                conditions.append(getattr(Submission, key) == value)
+                if key in Submission.__table__.columns:
+                    conditions.append(getattr(Submission, key) == value)
 
             # Get the submissions
             submissions = Submission.query
diff --git a/backend/tests/endpoints/submissions_test.py b/backend/tests/endpoints/submissions_test.py
index dca6bd83..4f6bc1c7 100644
--- a/backend/tests/endpoints/submissions_test.py
+++ b/backend/tests/endpoints/submissions_test.py
@@ -51,7 +51,7 @@ def test_get_submission_wrong_parameter(self, client: FlaskClient):
             "/submissions?parameter=0",
             headers = {"X-CSRF-TOKEN":get_csrf_from_login(client, "teacher")}
         )
-        assert response.status_code == 400
+        assert response.status_code == 200