CVE-2026-34730

Summary

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.

Affected Software

VendorProductVersion RangeStatus
copier-orgcopier< 9.14.1affected

Weaknesses

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

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

Additional References

References