diff --git a/litellm/proxy/_types.py b/litellm/proxy/_types.py
index 7fff640c497..39857984247 100644
--- a/litellm/proxy/_types.py
+++ b/litellm/proxy/_types.py
@@ -690,6 +690,13 @@ class LiteLLMRoutes(enum.Enum):
         "/organization/delete",
         "/organization/member_add",
         "/organization/member_update",
+        # member_delete is equally destructive as member_add / member_update
+        # and must be scoped the same way — otherwise it falls through to
+        # the management_routes / self_managed_routes path and lets any
+        # non-PROXY_ADMIN caller that reaches the route delete arbitrary
+        # org memberships without the organization_role_based_access_check
+        # that member_add / member_update trigger.
+        "/organization/member_delete",
     ]
 
     # Routes accessible by Admin Viewer (read-only admin access)
diff --git a/litellm/proxy/management_endpoints/organization_endpoints.py b/litellm/proxy/management_endpoints/organization_endpoints.py
index 25df9f0b0f7..670946ac0d8 100644
--- a/litellm/proxy/management_endpoints/organization_endpoints.py
+++ b/litellm/proxy/management_endpoints/organization_endpoints.py
@@ -1064,6 +1064,33 @@ async def organization_member_update(
                 },
             )
 
+        # Reject attempts to change the role of a global PROXY_ADMIN via
+        # org-scoped operations. An org-admin of any org could otherwise
+        # alter a PROXY_ADMIN user's per-org role, which has downstream
+        # effects on admin UI filtering and scope derivation.
+        target_user_row = await prisma_client.db.litellm_usertable.find_unique(
+            where={"user_id": data.user_id}
+        )
+        if target_user_row is not None and getattr(
+            target_user_row, "user_role", None
+        ) in (
+            LitellmUserRoles.PROXY_ADMIN.value,
+            LitellmUserRoles.PROXY_ADMIN_VIEW_ONLY.value,
+        ):
+            if (
+                user_api_key_dict.user_role
+                != LitellmUserRoles.PROXY_ADMIN.value
+            ):
+                raise HTTPException(
+                    status_code=403,
+                    detail={
+                        "error": (
+                            "Only PROXY_ADMIN may modify the organization "
+                            "role of a user who is a global PROXY_ADMIN."
+                        )
+                    },
+                )
+
         # Update member role
         if data.role is not None:
             await prisma_client.db.litellm_organizationmembership.update(