Cross-site scripting (XSS) vulnerability in Zope 2.8.x before 2.8.12, 2.9.x before 2.9.12, 2.10.x before 2.10.11, 2.11.x before 2.11.6, and 2.12.x before 2.12.3 allows remote attackers to inject arbitrary web script or HTML via vectors related to error messages.