Plone CMS until version 5.2.4 has a stored Cross-Site Scripting (XSS) vulnerability in the user fullname property and the file upload functionality. The user's input data is not properly encoded when being echoed back to the user. This data can be interpreted as executable code by the browser and allows an attacker to execute JavaScript in the context of the victim's browser if the victim opens a vulnerable page containing an XSS payload.
Products.PluggableAuthService is a pluggable Zope authentication and authorization framework. In Products.PluggableAuthService before version 2.6.0 there is an information disclosure vulnerability - everyone can list the names of roles defined in the ZODB Role Manager plugin if the site uses this plugin. The problem has been fixed in version 2.6.0. Depending on how you have installed Products.PluggableAuthService, you should change the buildout version pin to 2.6.0 and re-run the buildout, or if you used pip simply do `pip install "Products.PluggableAuthService>=2.6.0"`.
Plone before 5.2.3 allows XXE attacks via a feature that is protected by an unapplied permission of plone.schemaeditor.ManageSchemata (therefore, only available to the Manager role).
An open redirect on the login form (and possibly other places) in Plone 4.0 through 5.2.1 allows an attacker to craft a link to a Plone Site that, when followed, and possibly after login, will redirect to an attacker's site.
A privilege escalation issue in plone.app.contenttypes in Plone 4.3 through 5.2.1 allows users to PUT (overwrite) some content without needing write permission.
A member of the Plone 2.5-5.1rc1 site could set javascript in the home_page property of his profile, and have this executed when a visitor click the home page link on the author page.