diff --git a/files/qa-databases.conf b/files/qa-databases.conf
index 4a74abc4..c4fd3460 100644
--- a/files/qa-databases.conf
+++ b/files/qa-databases.conf
@@ -385,3 +385,16 @@ db_repl_8766_alias = $(dir_sampleDb)/qa_replication/db_repl_8766.fdb
 #
 db_sync_main_alias = $(dir_sampleDb)/qa_replication/db_sync_main.fdb
 db_sync_repl_alias = $(dir_sampleDb)/qa_replication/db_sync_repl.fdb
+
+# Tests for external table path validation.
+# Companion tests for FirebirdSQL/firebird#9121.
+
+tmp_external_file_access_denied_alias = $(dir_sampleDb)/qa/tmp_external_file_access_denied.fdb
+{
+    ExternalFileAccess = Restrict $(dir_sampleDb)/qa
+}
+
+tmp_external_file_allowed_alias = $(dir_sampleDb)/qa/tmp_external_file_allowed.fdb
+{
+    ExternalFileAccess = Restrict $(dir_sampleDb)/qa
+}
diff --git a/tests/functional/gtcs/test_external_file_access_denied.py b/tests/functional/gtcs/test_external_file_access_denied.py
new file mode 100644
index 00000000..c9d14a85
--- /dev/null
+++ b/tests/functional/gtcs/test_external_file_access_denied.py
@@ -0,0 +1,71 @@
+#coding:utf-8
+
+"""
+ID:          gtcs.external-file-access-denied
+FBTEST:      functional.gtcs.external_file_access_denied
+TITLE:       External file path outside configured directories is rejected at DDL time
+DESCRIPTION:
+  When ExternalFileAccess is restricted, creating an external table whose
+  file path is outside the allowed directory must be rejected during
+  CREATE TABLE.
+
+  Without the fix, CREATE TABLE succeeds and the invalid path is stored
+  in RDB$EXTERNAL_FILE. The access check is performed only when the
+  external file is opened.
+
+  With the fix, the path is validated while relation metadata is loaded,
+  so CREATE TABLE fails immediately.
+
+NOTES:
+  [08.08.2026] sunliqiang
+  The test database uses a dedicated databases.conf alias with
+  ExternalFileAccess restricted to its database directory.
+"""
+
+from pathlib import Path
+
+import pytest
+from firebird.qa import *
+
+
+REQUIRED_ALIAS = 'tmp_external_file_access_denied_alias'
+
+db = db_factory(filename='#' + REQUIRED_ALIAS)
+
+act = isql_act('db')
+
+
+@pytest.mark.version('>=4.0')
+def test_1(act: Action):
+
+    # Obtain the physical database location. The database is created inside
+    # the directory allowed by ExternalFileAccess.
+    with act.db.connect() as con:
+        cur = con.cursor()
+        cur.execute('select mon$database_name from mon$database')
+        db_path = Path(cur.fetchone()[0])
+
+    allowed_dir = db_path.parent
+
+    # Use a file in the parent directory, which is deliberately outside
+    # ExternalFileAccess = Restrict <allowed_dir>.
+    denied_file = allowed_dir.parent / 'ext_access_denied_test.dat'
+
+    external_file = str(denied_file).replace("'", "''")
+
+    sql = f"""
+        create table ext_escape external file '{external_file}'
+        (
+            line varchar(200)
+        );
+        exit;
+    """
+
+    act.expected_stderr = f"""
+Statement failed, SQLSTATE = 28000
+Use of external file at location {denied_file} is not allowed by server configuration
+"""
+
+    act.isql(switches=['-q'], input=sql)
+
+    assert act.clean_stderr == act.clean_expected_stderr
diff --git a/tests/functional/gtcs/test_external_file_allowed_dir.py b/tests/functional/gtcs/test_external_file_allowed_dir.py
new file mode 100644
index 00000000..a57275a8
--- /dev/null
+++ b/tests/functional/gtcs/test_external_file_allowed_dir.py
@@ -0,0 +1,84 @@
+#coding:utf-8
+
+"""
+ID:          gtcs.external-file-allowed-dir
+FBTEST:      functional.gtcs.external_file_allowed_dir
+TITLE:       External table in the allowed directory still works
+DESCRIPTION:
+  Regression test for external file path validation at metadata load time.
+
+  When ExternalFileAccess is restricted to the directory containing the
+  test database, an external table whose file is located inside that
+  directory must still work normally.
+
+NOTES:
+  [08.08.2026] sunliqiang
+  The test database uses a dedicated databases.conf alias with
+  ExternalFileAccess restricted to its database directory.
+"""
+
+from pathlib import Path
+
+import pytest
+from firebird.qa import *
+
+
+REQUIRED_ALIAS = 'tmp_external_file_allowed_alias'
+
+db = db_factory(filename='#' + REQUIRED_ALIAS)
+
+act = isql_act('db')
+
+
+expected_stdout = """
+ID                              42
+"""
+
+
+@pytest.mark.version('>=4.0')
+def test_1(act: Action):
+
+    # The database itself is located in the directory configured in
+    # ExternalFileAccess, so a sibling external file is guaranteed to
+    # be inside the allowed directory.
+    with act.db.connect() as con:
+        cur = con.cursor()
+        cur.execute('select mon$database_name from mon$database')
+        db_path = Path(cur.fetchone()[0])
+
+    ext_file = db_path.parent / 'ext_access_allowed_test.dat'
+
+    # Remove leftovers from an interrupted/failed previous test run.
+    ext_file.unlink(missing_ok=True)
+
+    external_file = str(ext_file).replace("'", "''")
+
+    sql = f"""
+        create table ext_ok external file '{external_file}'
+        (
+            id int
+        );
+        commit;
+
+        insert into ext_ok (id) values (42);
+        commit;
+
+        set list on;
+        select id from ext_ok;
+
+        drop table ext_ok;
+        commit;
+
+        exit;
+    """
+
+    act.expected_stdout = expected_stdout
+    act.expected_stderr = ""
+
+    try:
+        act.isql(switches=['-q'], input=sql)
+
+        assert act.clean_stdout == act.clean_expected_stdout
+        assert act.clean_stderr == act.clean_expected_stderr
+    finally:
+        ext_file.unlink(missing_ok=True)