Pypi · Copier · CVE-2026-53951
**Name of the Vulnerable Software and Affected Versions**
Copier versions 9.5.0 through 9.15.1
**Description**
An issue exists in the `trust` setting's prefix match within `copier/ settings.py` where the template URL is compared against a trusted prefix using `str.startswith` without path normalization. Because the URL is normalized during the actual fetch process (using `Path.resolve()` for local paths and libcurl dot-segment removal for HTTPS), a template reference containing `..` that textually starts with a trusted prefix can be granted trust. This allows an attacker-controlled template to execute `tasks`, `migrations`, or `jinja extensions` without the `--trust` prompt, leading to arbitrary command execution.
**Recommendations**
Update to version 9.15.2.