CVE-2026-53951 - Copier: trust-prefix bypass via path traversal runs tasks unprompted
CVE ID :CVE-2026-53951
Published : July 8, 2026, 4:16 p.m. | 29 minutes ago
Description :Copier is a library and CLI app for rendering project templates. In versions 9.5.0 through 9.15.1, the `trust` setting's prefix match (`copier/_settings.py`) compares the template URL against a trusted prefix with a raw `str.startswith` and no path normalization, while the URL is normalized when the template is actually fetched (`Path.resolve()` for local paths; libcurl dot-segment removal for `https`). A template reference that textually starts with a trusted prefix but contains `..` is therefore granted trust yet resolves to a different, attacker-controlled template, whose `tasks` / `migrations` / `jinja_extensions` then run without the `--trust` prompt — arbitrary command execution. Version 9.15.2 patches the issue.
Severity: 8.8 | HIGH
Visit the link for more details, such as CVSS details, affected products, timeline, and more...
Published : July 8, 2026, 4:16 p.m. | 29 minutes ago
Description :Copier is a library and CLI app for rendering project templates. In versions 9.5.0 through 9.15.1, the `trust` setting's prefix match (`copier/_settings.py`) compares the template URL against a trusted prefix with a raw `str.startswith` and no path normalization, while the URL is normalized when the template is actually fetched (`Path.resolve()` for local paths; libcurl dot-segment removal for `https`). A template reference that textually starts with a trusted prefix but contains `..` is therefore granted trust yet resolves to a different, attacker-controlled template, whose `tasks` / `migrations` / `jinja_extensions` then run without the `--trust` prompt — arbitrary command execution. Version 9.15.2 patches the issue.
Severity: 8.8 | HIGH
Visit the link for more details, such as CVSS details, affected products, timeline, and more...