{"cve":"CVE-2026-53951","nvd":{"published":"2026-07-08T16:16:30.623","modified":"2026-10-25T20:10:00.147","status":"Deferred","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\n(`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.","cvss_v4":{"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","score":8.8},"cvss_v3":null,"cwes":["CWE-22","CWE-94"],"references":["https://github.com/copier-org/copier/releases/tag/v9.15.2","https://github.com/copier-org/copier/security/advisories/GHSA-9gmc-jqmh-3rvm","https://github.com/copier-org/copier/security/advisories/GHSA-9gmc-jqmh-3rvm"],"products":[],"source":"nvd","synced_at":"2026-10-25T23:44:34.550481224+00:00"},"epss":{"cve":"CVE-2026-53951","score":0.00262,"percentile":0.17862,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-9gmc-jqmh-3rvm","url":"https://osv.dev/vulnerability/GHSA-9gmc-jqmh-3rvm","summary":"Copier has a trust-prefix bypass via path traversal that runs tasks unprompted","modified":"2026-09-10T12:25:32.628390125Z","packages":[{"ecosystem":"PyPI","name":"copier","purl":"pkg:pypi/copier","ranges":[">=9.5.0 <9.15.2"],"fixed":["9.15.2"]}]},{"id":"PYSEC-2026-3818","url":"https://osv.dev/vulnerability/PYSEC-2026-3818","summary":"Copier has a trust-prefix bypass via path traversal that runs tasks unprompted","modified":"2026-09-10T12:15:03.046958877Z","packages":[{"ecosystem":"PyPI","name":"copier","purl":"pkg:pypi/copier","ranges":[">=9.5.0 <9.15.2"],"fixed":["9.15.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}