CVE-2026-34730

Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, Copier’s _external_data feature allows a template to load YAML files using template-controlled paths. If untrusted templates are in scope, a malicious template can read attacker-chosen YAML-parseable local files that are accessible to the user running Copier and expose their contents in rendered output. This issue has been patched in version 9.14.1.

More information : https://github.com/copier-org/copier/commit/5413062eb17b73dc885f5e645cdc161e69ef641b