CVE-2026-34726
Copier `_subdirectory` allows template root escape via parent-directory traversal
- State
- Published
- Severity
- 4.4 Medium
- Published
- Apr 2, 2026
- Updated
- Apr 3, 2026
- Reserved
- Mar 30, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.4 Medium | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N | GitHub_M |
Weaknesses
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Products
| Product | Versions |
|---|---|
copiercopier-org |
|
References
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