Webform Multiple File Upload module for Drupal 7.x contains a cross-site scripting (XSS) vulnerability in the file name renderer. An unauthenticated attacker can exploit this vulnerability by uploading a file with a malicious filename containing JavaScript code (e.g., "<img src=1 onerror=alert(document.domain)>") to a Webform node with a Multifile field where file type validation is disabled. This allows the execution of arbitrary scripts in the context of the victim's browser. The issue is present in a third-party library and has been addressed in a patch available at  https://github.com/fyneworks/multifile/pull/44 . Users are advised to apply the provided patch or update to a fixed version of the module.