Copier has a trust-prefix bypass via path traversal that runs tasks unprompted

Date Aug 19, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product PyPI ยท copier
CVE CVE-2026-53951
High-risk advisory CVE-2026-53951

Summary

Copier has a trust-prefix bypass via path traversal that runs tasks unprompted

Why it matters

GitHub has published a reviewed security advisory for copier. Prioritize it with other application dependency updates, especially because EPSS places it in the 9% percentile.

Operator check

Check whether copier is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 8.8. EPSS probability: 0.2%; percentile: 9%.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.