{"id":"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.","aliases":["GHSA-p7q8-grrj-3m8w"],"modified":"2026-04-10T05:30:56.628789Z","published":"2025-08-18T16:36:46.621Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/55xxx/CVE-2025-55214.json","cwe_ids":["CWE-22"],"cna_assigner":"GitHub_M"},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/copier-org/copier","events":[{"introduced":"91f21c738cfcef2b47f6e58a308e94f062e2c9ea"},{"fixed":"165c85a1536c99af9422b70ac064cf1355347357"}]}],"versions":["v7.1.0","v7.2.0","v8.0.0","v8.1.0","v8.2.0","v8.3.0","v9.0.0","v9.0.1","v9.1.1","v9.2.0","v9.3.0","v9.3.1","v9.4.0","v9.4.1","v9.5.0","v9.6.0","v9.7.0","v9.7.1","v9.8.0","v9.9.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-55214.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"}]}