CVE-2026-34730

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.

PUBLISHED Reserved 2026-03-30 | Published 2026-04-02 | Updated 2026-04-03 | Assigner GitHub_M

Problem types

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Product status

References

github.com/...copier/security/advisories/GHSA-hgjq-p8cr-gg4h exploit

github.com/...copier/security/advisories/GHSA-hgjq-p8cr-gg4h

github.com/...ommit/5413062eb17b73dc885f5e645cdc161e69ef641b

github.com/copier-org/copier/releases/tag/v9.14.1

cve.org (CVE-2026-34730)

nvd.nist.gov (CVE-2026-34730)

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