CVE-2026-34726: Copier-Org Copier

Medium severity, CVSS 4.4. EPSS: 0.4% chance of exploitation in the next 30 days.

Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, 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 make Copier render files from the parent directory without --UNSAFE. This issue has been patched in version 9.14.1.

Affected products

• Copier-Org Copier: before 9.14.1 (fixed in 9.14.1)

Published 2026-04-02. Last modified 2026-07-24.