pdm is a Python package and dependency manager supporting the latest PEP standards. Versions prior to 2.27.0 are vulnerable to path traversal through write_to_fs. InstallDestination.write_to_fs() in src/pdm/installers/installers.py overrides the base class to add symlink/hardlink support but replaces the safe _path_with_destdir() (which validates via Path.resolve() + is_relative_to()) with a bare os.path.join() that performs no path validation. A malicious wheel with traversal entries can write arbitrary files. This issue has been fixed in version 2.27.0.
https://github.com/pdm-project/pdm/security/advisories/GHSA-78v8-vpjp-cjqh
Published: 2026-08-04
Updated: 2026-08-05
Base Score: 6.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 9.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity: Critical
Base Score: 8.4
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00047