Cross-site scripting (XSS) vulnerability in plugins/markdownplugin/markdown.plugin.php in b2evolution before 6.8.5 allows remote authenticated users to inject arbitrary web script or HTML via a javascript: URL.

The patch for directory traversal (CVE-2017-5480) in b2evolution version 6.8.4-stable has a bypass vulnerability. An attacker can use ..\/ to bypass the filter rule. Then, this attacker can exploit this vulnerability to delete or read any files on the server. It can also be used to determine whether a file exists.