GHSA-85V3-4M8G-HRH6 Copier `_subdirectory` allows template root escape via parent-directory traversal

Summary Copier's subdirectory setting is documented as the subdirectory to use as the template root. However, the current implementation accepts parent-directory traversal such as .. and uses it directly when selecting the template root. As a result, a template can escape its own directory and ma...

CVE-2025-22873 Improper access to parent directory of root in os

It was possible to improperly access the parent directory of an os.Root by opening a filename ending in "../". For example, Root.Open"../" would open the parent directory of the Root. This escape only permits opening the parent directory itself, not ancestors of the parent or files contained with...