{"id":"CVE-2026-34726","aliases":["GHSA-85v3-4m8g-hrh6","PYSEC-2026-2134"],"url":"https://o3.security/vulnerability/CVE-2026-34726","summary":"Copier `_subdirectory` allows template root escape via parent-directory traversal","details":"Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, Copier's _subdirectory setting is documented as the subdirectory to use as the template root. However, the current implementation accepts parent-directory traversal such as .. and uses it directly when selecting the template root. As a result, a template can escape its own directory and make Copier render files from the parent directory without --UNSAFE. This issue has been patched in version 9.14.1.","published":"2026-04-02T18:07:35.517Z","modified":"2026-08-07T11:49:20.454600558Z","cvss":{"score":4.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"copier","fixedVersion":"9.14.1"}],"fix":{"url":"https://github.com/copier-org/copier/commit/cb80a3ffc9c3787de3ed837e04ca29a0ff8ca3df","label":"copier-org/copier@cb80a3f"},"references":[{"type":"WEB","url":"https://github.com/copier-org/copier/releases/tag/v9.14.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34726.json"},{"type":"ADVISORY","url":"https://github.com/copier-org/copier/security/advisories/GHSA-85v3-4m8g-hrh6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34726"},{"type":"FIX","url":"https://github.com/copier-org/copier/commit/cb80a3ffc9c3787de3ed837e04ca29a0ff8ca3df"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:49:20.454600558Z"}}