{"id":"CVE-2025-55214","aliases":["GHSA-p7q8-grrj-3m8w","PYSEC-2026-1273"],"url":"https://o3.security/vulnerability/CVE-2025-55214","summary":"Copier safe template has filesystem write access outside destination path","details":"Copier library and CLI app for rendering project templates. From 7.1.0 to before 9.9.1, Copier suggests that it's safe to generate a project from a safe template, i.e. one that doesn't use unsafe features like custom Jinja extensions which would require passing the --UNSAFE,--trust flag. As it turns out, a safe template can currently write files outside the destination path where a project shall be generated or updated. This is possible when rendering a generated directory structure whose rendered path is either a relative parent path or an absolute path. Constructing such paths is possible using Copier's builtin pathjoin Jinja filter and its builtin _copier_conf.sep variable, which is the platform-native path separator. This way, a malicious template author can create a template that overwrites arbitrary files (according to the user's write permissions), e.g., to cause havoc. This vulnerability is fixed in 9.9.1.","published":"2025-08-18T16:36:46.621Z","modified":"2026-08-08T03:47:56.307826764Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"copier","fixedVersion":"9.9.1"}],"fix":{"url":"https://github.com/copier-org/copier/commit/fdbc0167cc22780b497e4db176feaf6f024757d6","label":"copier-org/copier@fdbc016"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/55xxx/CVE-2025-55214.json"},{"type":"ADVISORY","url":"https://github.com/copier-org/copier/security/advisories/GHSA-p7q8-grrj-3m8w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-55214"},{"type":"FIX","url":"https://github.com/copier-org/copier/commit/fdbc0167cc22780b497e4db176feaf6f024757d6"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-08T03:47:56.307826764Z"}}