diff --git a/web/pgacloud/providers/google.py b/web/pgacloud/providers/google.py
index f7c93ec7715..5d34b50c824 100644
--- a/web/pgacloud/providers/google.py
+++ b/web/pgacloud/providers/google.py
@@ -8,12 +8,23 @@
 # ##########################################################################
 import json
 import os
+import sys
 import time
 
 from utils.io import debug, error, output
 from utils.misc import get_my_ip, get_random_id
 from providers._abstract import AbsProvider
 
+# pgAdmin only authenticates to Google via google-auth, never the
+# long-deprecated oauth2client. googleapiclient still tries to import
+# oauth2client optionally, and on packaged installs the venv inherits the
+# system site-packages (--system-site-packages, see issue #7173) where a
+# stale oauth2client and an incompatible pyOpenSSL may be present. That
+# optional import drags in the broken pyOpenSSL and crashes with "module
+# 'lib' has no attribute 'GEN_EMAIL'". Blocking the module here makes
+# googleapiclient fall back to google-auth cleanly. See issue #10110.
+sys.modules.setdefault('oauth2client', None)
+
 from googleapiclient import discovery
 from googleapiclient.errors import HttpError
 from google.auth.transport.requests import Request
diff --git a/web/pgadmin/misc/cloud/google/__init__.py b/web/pgadmin/misc/cloud/google/__init__.py
index b6aafa72d24..20fb883593c 100644
--- a/web/pgadmin/misc/cloud/google/__init__.py
+++ b/web/pgadmin/misc/cloud/google/__init__.py
@@ -10,6 +10,7 @@
 # Google Cloud Deployment Implementation
 import json
 import os
+import sys
 from urllib.parse import unquote
 
 from config import root
@@ -25,6 +26,18 @@
 from flask_babel import gettext as _
 
 from oauthlib.oauth2 import AccessDeniedError
+
+# pgAdmin only authenticates to Google via google-auth and
+# google-auth-oauthlib, never the long-deprecated oauth2client.
+# googleapiclient still tries to import oauth2client optionally, and on
+# packaged installs the venv inherits the system site-packages
+# (--system-site-packages, see issue #7173) where a stale oauth2client and
+# an incompatible pyOpenSSL may be present. That optional import drags in
+# the broken pyOpenSSL and aborts startup with "module 'lib' has no
+# attribute 'GEN_EMAIL'". Blocking the module here makes googleapiclient
+# fall back to google-auth cleanly. See issue #10110.
+sys.modules.setdefault('oauth2client', None)
+
 from googleapiclient import discovery
 from googleapiclient.errors import HttpError
 from google_auth_oauthlib.flow import InstalledAppFlow
diff --git a/web/pgadmin/misc/cloud/google/tests/test_google_oauth2client_blocked.py b/web/pgadmin/misc/cloud/google/tests/test_google_oauth2client_blocked.py
new file mode 100644
index 00000000000..14930ecec29
--- /dev/null
+++ b/web/pgadmin/misc/cloud/google/tests/test_google_oauth2client_blocked.py
@@ -0,0 +1,58 @@
+##########################################################################
+#
+# pgAdmin 4 - PostgreSQL Tools
+#
+# Copyright (C) 2013 - 2026, The pgAdmin Development Team
+# This software is released under the PostgreSQL Licence
+#
+##########################################################################
+
+"""
+Regression test for issue #10110.
+
+On packaged installs the venv inherits the system site-packages
+(--system-site-packages, see issue #7173). When a stale ``oauth2client``
+and an incompatible ``pyOpenSSL`` live there, googleapiclient's optional
+``import oauth2client`` drags in the broken pyOpenSSL and aborts pgAdmin
+startup with "module 'lib' has no attribute 'GEN_EMAIL'".
+
+The cloud.google module guards against this by parking a ``None`` sentinel
+under ``sys.modules['oauth2client']`` before importing googleapiclient, so
+the optional import fails cleanly and google-auth is used instead.
+"""
+
+import sys
+import unittest
+
+from pgadmin.utils.route import BaseTestGenerator
+
+
+class _SkipServerSetUpMixin:
+    """Skip BaseTestGenerator's Postgres connection — pure logic tests."""
+
+    def setUp(self):
+        unittest.TestCase.setUp(self)
+
+
+class TestOauth2ClientBlockedOnGoogleImport(
+        _SkipServerSetUpMixin, BaseTestGenerator):
+    """Importing cloud.google must keep googleapiclient off oauth2client."""
+
+    scenarios = (('default', {}),)
+
+    def runTest(self):
+        # Importing the module installs the sentinel as a side effect.
+        import pgadmin.misc.cloud.google  # noqa: F401
+
+        # The sentinel must be in place so googleapiclient never imports
+        # the deprecated oauth2client (and the pyOpenSSL it would pull in).
+        self.assertIsNone(
+            sys.modules.get('oauth2client', 'missing'),
+            "cloud.google must park a None sentinel under "
+            "sys.modules['oauth2client'] to block the optional import")
+
+        # googleapiclient must consequently report no oauth2client support.
+        import googleapiclient._auth as _auth
+        self.assertFalse(
+            _auth.HAS_OAUTH2CLIENT,
+            "googleapiclient must fall back to google-auth, not oauth2client")