PYSEC-2026-1272 Copier safe template has arbitrary filesystem write access via directory symlinks when _preserve_symlinks: true

Impact 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...

Copier safe template has arbitrary filesystem write access via directory symlinks when _preserve_symlinks: true

ImpactCopier 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...

Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false

ImpactCopier 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...

PYSEC-2026-1273 Copier's safe template has filesystem write access outside destination path

Impact 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...

PYSEC-2026-1271 Copier's safe template has arbitrary filesystem read/write access

Impact Copier's current security model shall restrict filesystem access through Jinja: - Files can only be read using % include ... %, which is limited by Jinja to reading files from the subtree of the local template clone in our case. - Files are written in the destination directory according to...

Copier's safe template has filesystem write access outside destination path

ImpactCopier 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...

CVE-2026-34730

Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, Copier's externaldata 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 fil...

CVE-2026-34726

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...

CVE-2026-34726

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...

PYSEC-2026-2134

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...

CVE-2026-34730

Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, Copier's externaldata 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 fil...

CVE-2026-34730

Summary: CVE-2026-34730 affects Copier prior to version 9.14.1, where the optional _external_data feature allows template-controlled paths to load YAML files. This can enable destination-external reads, including parent-directory traversal (e.g., ../secret.yml) and absolute paths, exposing the co...

CVE-2026-34730 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 externaldata 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 fil...

CVE-2026-34730 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 externaldata 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 fil...

CVE-2026-34730 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 externaldata 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 fil...

CVE-2026-34726

CVE-2026-34726 affects Copier (library/CLI) prior to version 9.14.1. The issue stems from the _subdirectory setting, which is documented as the template root but can accept directory traversal like .., and is used directly to compute the template root. This allows a template to escape its own dir...

CVE-2026-34726 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...

CVE-2026-34726

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...

CVE-2026-34726 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...

CVE-2026-34726 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...