CVE-2026-34730
Copier `_external_data` allows path traversal and absolute-path local file read without unsafe mode
- State
- Published
- Severity
- 5.5 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 _external_data feature allows a template to load YAML files using template-controlled paths. If untrusted templates are in scope, a malicious template can read attacker-chosen YAML-parseable local files that are accessible to the user running Copier and expose their contents in rendered output. This issue has been patched in version 9.14.1.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.5 Medium | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/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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