diff --git a/glance/common/wsgi_app.py b/glance/common/wsgi_app.py
index e505e14c75..51a92e2737 100644
--- a/glance/common/wsgi_app.py
+++ b/glance/common/wsgi_app.py
@@ -65,6 +65,7 @@ def _setup_os_profiler():
 
 
 def init_app():
+    config.set_config_defaults()
     config_files = _get_config_files()
     CONF([], project='glance', default_config_files=config_files)
     logging.setup(CONF, "glance")
diff --git a/releasenotes/notes/bug-1861334-ebc2026b85675d47.yaml b/releasenotes/notes/bug-1861334-ebc2026b85675d47.yaml
new file mode 100644
index 0000000000..f57542e4ca
--- /dev/null
+++ b/releasenotes/notes/bug-1861334-ebc2026b85675d47.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Bug 1861334_: cors config defaults not used when Glance is run as WSGI app
+
+    .. _1861334: https://bugs.launchpad.net/glance/+bug/1861334