diff --git a/airflow-core/docs/core-concepts/auth-manager/index.rst b/airflow-core/docs/core-concepts/auth-manager/index.rst
index 258b9aae3622a..be626edde7fe4 100644
--- a/airflow-core/docs/core-concepts/auth-manager/index.rst
+++ b/airflow-core/docs/core-concepts/auth-manager/index.rst
@@ -201,6 +201,7 @@ The following methods aren't required to override to have a functional Airflow a
 * ``batch_is_authorized_pool``: Batch version of ``is_authorized_pool``. If not overridden, it will call ``is_authorized_pool`` for every single item.
 * ``batch_is_authorized_variable``: Batch version of ``is_authorized_variable``. If not overridden, it will call ``is_authorized_variable`` for every single item.
 * ``get_authorized_dag_ids``: Return the list of Dag IDs the user has access to.  If not overridden, it will call ``is_authorized_dag`` for every single Dag available in the environment.
+* ``is_authorized_hitl_task``: Return whether the user is authorized to approve or reject a Human-in-the-loop (HITL) task. Override this method to implement custom authorization logic for HITL tasks. If not overridden, it checks if the user's ID is in the assigned users list.
 
   * Note: To filter the results of ``get_authorized_dag_ids``, it is recommended that you define the filtering logic in your ``filter_authorized_dag_ids`` method. For example, this may be useful if you rely on per-Dag access controls derived from one or more fields on a given Dag (e.g. Dag tags).
   * This method requires an active session with the Airflow metadata database. As such, overriding the ``get_authorized_dag_ids`` method is an advanced use case, which should be considered carefully -- it is recommended you refer to the :doc:`../../database-erd-ref`.
diff --git a/airflow-core/newsfragments/59399.feature.rst b/airflow-core/newsfragments/59399.feature.rst
new file mode 100644
index 0000000000000..4017b3ec0e946
--- /dev/null
+++ b/airflow-core/newsfragments/59399.feature.rst
@@ -0,0 +1 @@
+Add ``is_authorized_hitl_task()`` method to check whether a user a is authorized to approve a HITL task
diff --git a/airflow-core/src/airflow/api_fastapi/auth/managers/base_auth_manager.py b/airflow-core/src/airflow/api_fastapi/auth/managers/base_auth_manager.py
index b8656cd068f10..d7d2acabe593e 100644
--- a/airflow-core/src/airflow/api_fastapi/auth/managers/base_auth_manager.py
+++ b/airflow-core/src/airflow/api_fastapi/auth/managers/base_auth_manager.py
@@ -318,6 +318,18 @@ def filter_authorized_menu_items(self, menu_items: list[MenuItem], *, user: T) -
         :param user: the user
         """
 
+    def is_authorized_hitl_task(self, *, assigned_users: set[str], user: T) -> bool:
+        """
+        Check if a user is allowed to approve/reject a HITL task.
+
+        By default, checks if the user's ID is in the assigned_users set.
+        Auth managers can override this method to implement custom logic.
+
+        :param assigned_users: set of user IDs assigned to the task
+        :param user: the user to check authorization for
+        """
+        return user.get_id() in assigned_users
+
     def batch_is_authorized_connection(
         self,
         requests: Sequence[IsAuthorizedConnectionRequest],
diff --git a/airflow-core/src/airflow/api_fastapi/auth/managers/simple/simple_auth_manager.py b/airflow-core/src/airflow/api_fastapi/auth/managers/simple/simple_auth_manager.py
index 28e3c172f8995..09250168e14ed 100644
--- a/airflow-core/src/airflow/api_fastapi/auth/managers/simple/simple_auth_manager.py
+++ b/airflow-core/src/airflow/api_fastapi/auth/managers/simple/simple_auth_manager.py
@@ -272,6 +272,26 @@ def filter_authorized_menu_items(
     ) -> list[MenuItem]:
         return menu_items
 
+    def is_authorized_hitl_task(self, *, assigned_users: set[str], user: SimpleAuthManagerUser) -> bool:
+        """
+        Check if a user is allowed to approve/reject a HITL task.
+
+        When simple_auth_manager_all_admins=True, all authenticated users are allowed
+        to approve/reject any task. Otherwise, the user must be in the assigned_users set.
+        """
+        is_simple_auth_manager_all_admins = conf.getboolean("core", "simple_auth_manager_all_admins")
+
+        if is_simple_auth_manager_all_admins:
+            # In all-admin mode, everyone is allowed
+            return True
+
+        # If no assigned_users specified, allow access
+        if not assigned_users:
+            return True
+
+        # Delegate to parent class for the actual authorization check
+        return super().is_authorized_hitl_task(assigned_users=assigned_users, user=user)
+
     def get_fastapi_app(self) -> FastAPI | None:
         """
         Specify a sub FastAPI application specific to the auth manager.
diff --git a/airflow-core/src/airflow/api_fastapi/core_api/routes/public/hitl.py b/airflow-core/src/airflow/api_fastapi/core_api/routes/public/hitl.py
index 361d5faf933f2..ba7e29a123b81 100644
--- a/airflow-core/src/airflow/api_fastapi/core_api/routes/public/hitl.py
+++ b/airflow-core/src/airflow/api_fastapi/core_api/routes/public/hitl.py
@@ -51,7 +51,12 @@
     UpdateHITLDetailPayload,
 )
 from airflow.api_fastapi.core_api.openapi.exceptions import create_openapi_http_exception_doc
-from airflow.api_fastapi.core_api.security import GetUserDep, ReadableTIFilterDep, requires_access_dag
+from airflow.api_fastapi.core_api.security import (
+    GetUserDep,
+    ReadableTIFilterDep,
+    get_auth_manager,
+    requires_access_dag,
+)
 from airflow.api_fastapi.logging.decorators import action_logging
 from airflow.models.dag_version import DagVersion
 from airflow.models.dagrun import DagRun
@@ -155,7 +160,9 @@ def update_hitl_detail(
         user_id = str(user_id)
     hitl_user = HITLUser(id=user_id, name=user_name)
     if hitl_detail_model.assigned_users:
-        if hitl_user not in hitl_detail_model.assigned_users:
+        # Convert assigned_users list to set of user IDs for authorization check
+        assigned_user_ids = {assigned_user["id"] for assigned_user in hitl_detail_model.assigned_users}
+        if not get_auth_manager().is_authorized_hitl_task(assigned_users=assigned_user_ids, user=user):
             log.error("User=%s (id=%s) is not a respondent for the task", user_name, user_id)
             raise HTTPException(
                 status.HTTP_403_FORBIDDEN,
diff --git a/airflow-core/tests/unit/api_fastapi/auth/managers/simple/test_simple_auth_manager.py b/airflow-core/tests/unit/api_fastapi/auth/managers/simple/test_simple_auth_manager.py
index 15bbb19a1a212..de58efca7e1a8 100644
--- a/airflow-core/tests/unit/api_fastapi/auth/managers/simple/test_simple_auth_manager.py
+++ b/airflow-core/tests/unit/api_fastapi/auth/managers/simple/test_simple_auth_manager.py
@@ -268,3 +268,25 @@ def test_filter_authorized_menu_items(self, auth_manager):
             items, user=SimpleAuthManagerUser(username="test", role=None)
         )
         assert results == items
+
+    @pytest.mark.parametrize(
+        ("all_admins", "user_id", "assigned_users", "expected"),
+        [
+            # When simple_auth_manager_all_admins=True, any user should be allowed
+            (True, "user1", {"user2"}, True),
+            (True, "user2", {"user2"}, True),
+            (True, "admin", {"test_user"}, True),
+            # When simple_auth_manager_all_admins=False, user must be in assigned_users
+            (False, "user1", {"user1"}, True),
+            (False, "user2", {"user1"}, False),
+            (False, "admin", {"test_user"}, False),
+            # When no assigned_users, allow access
+            (False, "user1", set(), True),
+        ],
+    )
+    def test_is_authorized_hitl_task(self, auth_manager, all_admins, user_id, assigned_users, expected):
+        """Test is_authorized_hitl_task method with different configurations."""
+        with conf_vars({("core", "simple_auth_manager_all_admins"): str(all_admins)}):
+            user = SimpleAuthManagerUser(username=user_id, role="user")
+            result = auth_manager.is_authorized_hitl_task(assigned_users=assigned_users, user=user)
+            assert result == expected