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.
Affected products
copier-org: copier
References4
- github.com/copier-org/copier/security/advisories/GHSA-85v3-4m8g… ExploitVendor Advisory
- github.com/copier-org/copier/security/advisories/GHSA-85v3-4m8g… ExploitVendor Advisory
- github.com/copier-org/copier/commit/cb80a3ffc9c3787de3ed837e04c… Patch
- github.com/copier-org/copier/releases/tag/v9.14.1 Release Notes
Metrics
- CVSS 3.1
-
4.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 34 · as of 12 November 2026
- CWE
- CWE-22
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.