Cross-site scripting (XSS) vulnerability in the Hashcash module 6.x-2.x before 6.x-2.6 and 7.x-2.x before 7.x-2.2 for Drupal, when "Log failed hashcash" is enabled, allows remote attackers to inject arbitrary web script or HTML via an invalid token, which is not properly handled when administrators use the Database logging module.