diff --git a/yt_dlp/extractor/softwhiteunderbelly.py b/yt_dlp/extractor/softwhiteunderbelly.py
index 41f161060..e13f6ce8f 100644
--- a/yt_dlp/extractor/softwhiteunderbelly.py
+++ b/yt_dlp/extractor/softwhiteunderbelly.py
@@ -63,8 +63,7 @@ def _perform_login(self, username, password):
                 'email': username,
                 'password': password,
                 'authenticity_token': self._html_search_regex(
-                    r'name=["\']authenticity_token["\'] value=["\'](.+?)["\']', signin_page, 'authenticity_token',
-                ),
+                    r'name=["\']authenticity_token["\']\s+value=["\']([^"\']+)', signin_page, 'authenticity_token'),
                 'utf8': True,
             }),
         )