CVE-2026-34726 Details
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.
A directory traversal vulnerability has been identified in Copier versions prior to 9.14.1. The issue arises in the `_subdirectory` setting, which is intended to specify a subdirectory within the template root. However, the implementation improperly allows parent-directory traversal, enabling templates to escape their designated directories and access files from the parent directory. This can occur without the `--UNSAFE` flag, potentially leading to the unintentional inclusion of sensitive files in the rendering process.
Users can update to Copier version 9.14.1 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 3, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/copier-org/copier/security/advisories/GHSA-85v3-4m8g-hrh6 | CISA-ADP | ExploitVendor Advisory |
| https://github.com/copier-org/copier/commit/cb80a3ffc9c3787de3ed837e04ca29a0ff8ca3df | [email protected] | Patch |
| https://github.com/copier-org/copier/releases/tag/v9.14.1 | [email protected] | Release Notes |
| https://github.com/copier-org/copier/security/advisories/GHSA-85v3-4m8g-hrh6 | [email protected] | ExploitVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-22 | Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| copier-org copier | < 9.14.1 |
CPE
Remediation
| |
Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 3, 2026 | Initial Analysis | [email protected] |
| Apr 3, 2026 | CVE Modified | CISA-ADP |
| Apr 2, 2026 | New CVE Received | [email protected] |