Fix RLS bypass via nested VALUES subquery

superset/sql/parse.py

@@ -1373,6 +1373,22 @@ def extract_tables_from_statement(
             if isinstance(source, exp.Table) and not is_cte(source, scope)
         ]
 
+        # Use of `traverse_scope` doesn't always catch tables in subqueries within
+        # `VALUES` clauses, so we need to search for them explicitly.
+        # See https://github.com/apache/superset/issues/31599 for more details.
+        cte_names = {
+            cte.alias
+            for cte in statement.find_all(exp.CTE)
+            if isinstance(cte.alias, str)
+        }
+        for value in statement.find_all(exp.Values):
+            for table in value.find_all(exp.Table):
+                # If the table is not a CTE, it should be treated as a source.
+                # This is a heuristic, as we can't easily check for CTEs in scopes
+                # without traversing them.
+                if table.name not in cte_names:
+                    sources.append(table)
+
     return {
         Table(
             source.name,

tests/unit_tests/sql/parse_tests_vulnerability.py

@@ -0,0 +1,41 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+import unittest
+from superset.sql.parse import SQLStatement
+
+class TestSqlParseVulnerability(unittest.TestCase):
+    def test_values_subquery_extraction(self):
+        """
+        Test that tables hidden inside a VALUES clause with a nested subquery are extracted.
+        """
+        sql = "SUM(revenue) + (SELECT \"r\" FROM (VALUES((SELECT COUNT(*) FROM sales WHERE country='CA'))) v(\"r\"))"
+        statement = SQLStatement(sql, engine="postgresql")
+        tables = statement.tables
+
+        self.assertIn("sales", [t.table for t in tables], "Should extract 'sales' table from nested VALUES subquery")
+
+    def test_normal_subquery_extraction(self):
+        """
+        Test that normal subqueries work as expected.
+        """
+        sql = "SELECT * FROM (SELECT * FROM sales) AS sub"
+        statement = SQLStatement(sql, engine="postgresql")
+        tables = statement.tables
+        self.assertIn("sales", [t.table for t in tables])
+
+if __name__ == '__main__':
+    unittest.main()