Solspace Freeform plugin for Craft CMS 5.x is a super flexible form-building tool. From 5.0.0 through 5.10.13, submitted values from public

Solspace Freeform plugin for Craft CMS 5.x is a super flexible form-building tool. From 5.0.0 through 5.10.13, submitted values from public Freeform forms can be evaluated by the isolated Twig renderer when rendered into HTML attributes. An unauthenticated attacker can place Twig expressions in submitted field values, including value attributes, and receive evaluated PHP, operating-system, or Craft filesystem-path constants in the form response. The isolated context was not shown to expose Craft globals, environment variables, credentials, arbitrary files, or code execution, so the confirmed impact is limited server and environment information disclosure and possible rendering errors. This issue is fixed in version 5.10.14.