diff --git a/src/yunohost/app.py b/src/yunohost/app.py
index 9c76e73eb..a3244abe1 100644
--- a/src/yunohost/app.py
+++ b/src/yunohost/app.py
@@ -2470,6 +2470,7 @@ class PasswordArgumentParser(YunoHostArgumentFormatParser):
     hide_user_input_in_prompt = True
     argument_type = "password"
     default_value = ""
+    forbidden_chars = "{}"
 
     def parse_question(self, question, user_answers):
         question = super(PasswordArgumentParser, self).parse_question(question, user_answers)
@@ -2479,6 +2480,12 @@ class PasswordArgumentParser(YunoHostArgumentFormatParser):
 
         return question
 
+    def _post_parse_value(self, question):
+        if any(char in question.value for char in self.forbidden_chars):
+            raise YunohostError('pattern_password_app', forbidden_chars=self.forbidden_chars)
+
+        return super(PasswordArgumentParser, self)._post_parse_value(question)
+
 
 class PathArgumentParser(YunoHostArgumentFormatParser):
     argument_type = "path"
diff --git a/src/yunohost/tests/test_apps_arguments_parsing.py b/src/yunohost/tests/test_apps_arguments_parsing.py
index 1ea73cc0a..9576ce0bf 100644
--- a/src/yunohost/tests/test_apps_arguments_parsing.py
+++ b/src/yunohost/tests/test_apps_arguments_parsing.py
@@ -8,7 +8,7 @@ from collections import OrderedDict
 from moulinette import msignals
 
 from yunohost import domain, user, app
-from yunohost.app import _parse_args_in_yunohost_format
+from yunohost.app import _parse_args_in_yunohost_format, PasswordArgumentParser
 from yunohost.utils.error import YunohostError
 
 
@@ -359,6 +359,21 @@ def test_parse_args_in_yunohost_format_password_input_test_ask_with_help():
         assert help_text in prompt.call_args[0][0]
 
 
+def test_parse_args_in_yunohost_format_password_bad_chars():
+    questions = [
+        {
+            "name": "some_password",
+            "type": "password",
+            "ask": "some question",
+            "example": "some_value",
+        }
+    ]
+
+    for i in PasswordArgumentParser.forbidden_chars:
+        with pytest.raises(YunohostError):
+            _parse_args_in_yunohost_format({"some_password": i * 8}, questions)
+
+
 def test_parse_args_in_yunohost_format_path():
     questions = [{"name": "some_path", "type": "path",}]
     answers = {"some_path": "some_value"}