CVE-2021-33511
Plone though 5.2.4 allows SSRF via the lxml parser. This affects Diazo themes, Dexterity TTW schemas, and modeleditors in plone.app.theming, plone.app.dexterity, and plone.supermodel.
Date published : 2021-05-21
https://plone.org/security/hotfix/20210518/server-side-request-forgery-via-lxml-parser