diff --git a/CHANGELOG b/CHANGELOG
index 5f5c2a0f1..5663e9c51 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -8,6 +8,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 
+## [2.35.2] - 2026-03-17
+### Fixed
+- [PORTAL] [TEMPLATE] Wrong media-type for base64 encoded images
+
+
 ## [2.35.1] - 2026-03-06
 ### Added
 - [API_PARSER] Add api_collector parameters in the returned representation of Frontends through APIs
diff --git a/vulture_os/authentication/portal_template/models.py b/vulture_os/authentication/portal_template/models.py
index cc54caba3..7ceeabc1a 100644
--- a/vulture_os/authentication/portal_template/models.py
+++ b/vulture_os/authentication/portal_template/models.py
@@ -417,8 +417,8 @@ def get_image_uri(self):
         :return: String containing the URI of the image.
         """
         try:
-            url = 'portal_statics/{}'.format(self.uid)
-        except:
+            url = f"portal_statics/{self.uid}"
+        except Exception:
             return None
 
         return url
@@ -429,7 +429,7 @@ def get_as_html(self):
         :return: A string with pre-formatted html for the image
         """
 
-        return "<img src='data:image/{};base64,{}'/>".format(self.image_type, self.content)
+        return f"<img src='data:{self.image_type};base64,{self.content}'/>"
 
     def create_preview_html(self):
         """
@@ -437,4 +437,4 @@ def create_preview_html(self):
         :return: A string with pre-formatted html for the image
         """
 
-        return "data:image/{};base64,{}".format(self.image_type, self.content)
+        return f"data:{self.image_type};base64,{self.content}"
diff --git a/vulture_os/portal/system/authentications.py b/vulture_os/portal/system/authentications.py
index 9b5a3c2ca..bf28d0b74 100644
--- a/vulture_os/portal/system/authentications.py
+++ b/vulture_os/portal/system/authentications.py
@@ -341,7 +341,7 @@ def authenticate(self, request):
     def ask_credentials_response(self, **kwargs):
         if self.workflow.authentication.enable_captcha:
             captcha_key = self.redis_portal_session.register_captcha(self.workflow.id)
-            captcha = "data:image/image/png;base64," + b64encode(ImageCaptcha().generate(captcha_key).read()).decode()
+            captcha = "data:image/png;base64," + b64encode(ImageCaptcha().generate(captcha_key).read()).decode()
         else:
             captcha = False