Copier-org vulnerabilities
Published CVEs affecting Copier-org products: 4 record(s), with severity, exploitation and fixes.
CVE-2026-34730
Medium · 5.5
CWE-22 Apr 2, 2026
Copier `_external_data` allows path traversal and absolute-path local file read without unsafe mode
Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, Copier's _external_data feature allows a template to load YAML files using template-controlled paths. If untrusted templates are in scope, a malicious template can read attacker-chosen YAML-parseable local files that are accessible to the user running Copier and expose their contents in rendered output. This issue has been patched in version 9.14.1.
CVE-2026-34726
Medium · 4.4
CWE-22 Apr 2, 2026
Copier `_subdirectory` allows template root escape via parent-directory traversal
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.
CVE-2026-23986
High · 7.1
CWE-61 Jan 21, 2026
Copier safe template has arbitrary filesystem write access via directory symlinks when _preserve_symlinks: true
Copier is a library and CLI app for rendering project templates. Prior to version 9.11.2, 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 to arbitrary directories outside the destination path by using directory a symlink along with `_preserve_symlinks: true` and a generated directory structure whose rendered path is inside the symlinked directory. 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. Version 9.11.2 patches the issue.
CVE-2026-23968
Medium · 5.5
CWE-61 Jan 21, 2026
Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false
Copier is a library and CLI app for rendering project templates. Prior to version 9.11.2, 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 include arbitrary files/directories outside the local template clone location by using symlinks along with `_preserve_symlinks: false` (which is Copier's default setting). Version 9.11.2 patches the issue.