1 files changed, 4 insertions, 0 deletions
diff --git a/program/lib/Roundcube/rcube_html2text.php b/program/lib/Roundcube/rcube_html2text.php
index 01362e6fb..3b4508da9 100644
--- a/program/lib/Roundcube/rcube_html2text.php
+++ b/program/lib/Roundcube/rcube_html2text.php
@@ -616,6 +616,10 @@ class rcube_html2text
 
                     break;
                 }
+                // abort on invalid tag structure (e.g. no closing tag found)
+                else {
+                    break;
+                }
             }
             while ($end || $next);
         }