CVE-2026-34730
MEDIUMCopier `_external_data` allows path traversal and absolute-path local file read without unsafe mode
Title source: cnaDescription
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 v3
5.5
EPSS
0.0001
EPSS Percentile
0.9%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-22
Status
published
Products (2)
copier-org/copier
< 9.14.1 (2 CPE variants)
pypi/copier
0 - 9.14.1PyPI
Published
Apr 02, 2026
Tracked Since
Apr 03, 2026