diff --git a/flask_cas/routing.py b/flask_cas/routing.py
index cb2b532cc..c88e7d802 100644
--- a/flask_cas/routing.py
+++ b/flask_cas/routing.py
@@ -2,10 +2,12 @@
 Routes for CAS authentication
 Modified for ScoDoc
 """
+
 import re
 import ssl
 from urllib.error import URLError
 from urllib.request import urlopen
+from xml.parsers.expat import ExpatError
 
 import flask
 from flask import current_app, request
@@ -170,8 +172,8 @@ def validate(ticket):
             if "cas:authenticationSuccess" in xml_from_dict["cas:serviceResponse"]
             else False
         )
-    except ValueError:
-        current_app.logger.error("CAS returned unexpected result")
+    except (ValueError, ExpatError) as exc:
+        current_app.logger.error(f"CAS returned unexpected result: {exc}")
         if cas_error_callback:
             cas_error_callback("réponse invalide du serveur CAS")
     except URLError:
diff --git a/sco_version.py b/sco_version.py
index c5da9f968..56bbddc83 100644
--- a/sco_version.py
+++ b/sco_version.py
@@ -3,7 +3,7 @@
 
 "Infos sur version ScoDoc"
 
-SCOVERSION = "9.7.52"
+SCOVERSION = "9.7.53"
 
 SCONAME = "ScoDoc"