Most recent entries from all

BREW-pdm-CVE-2026-47763 — pdm: Project-Local State and Config Writes Follow Symlinks

Affected: Homebrew: pdm

pdm is a Python package and dependency manager supporting the latest PEP standards. In versions prior to 2.27.0, pdm writes several project-local state or configuration files without symlink protection. If a malicious repository places those files as symlinks, local PDM operations can overwrite the symlink targets. This creates an arbitrary file clobber primitive relative to the privileges of the invoking user. Config.__init__() resolves the project-local pdm.toml path and _save_config() writes to the resolved target. If PROJECT_ROOT/pdm.toml is a symlink to another file, pdm config -l ... updates the target file instead of refusing the write. The same general problem exists for other project-local persistence paths that are written directly with no lstat / O_NOFOLLOW protection. For the pdm.toml PoC specifically, the target file must already contain parseable TOML. Otherwise the load step fails before the write path is reached. That parser constraint does not apply to the .pdm-python or .python-version sinks. This issue has been fixed in version 2.27.0.

CVE-2026-47763 — pdm: Project-Local State and Config Writes Follow Symlinks

Affected: pdm-project pdm

GHSA-ghq2-5c67-fprm — PDM: Project-Local State and Config Writes Follow Symlinks

Affected: PyPI: pdm

## Summary

PDM writes several project-local state or configuration files without symlink protection. If a malicious repository places those files as symlinks, local PDM operations can overwrite the symlink targets.

This creates an arbitrary file clobber primitive relative to the privileges of the invoking user.

## Affected Behavior

- Project-local config writes can affect files outside the repository - The most stable demonstrated sink is `pdm.toml` - Related sinks include `.pdm-python` and `.python-version`

## Affected Code

- `src/pdm/project/config.py:303-350` - `src/pdm/project/core.py:209-217` - `src/pdm/cli/commands/use.py:187-189`

## Technical Details

`Config.__init__()` resolves the project-local `pdm.toml` path and `_save_config()` writes to the resolved target. If `PROJECT_ROOT/pdm.toml` is a symlink to another file, `pdm config -l ...` updates the target file instead of refusing the write.

The same general problem exists for other project-local persistence paths that are written directly with no `lstat` / `O_NOFOLLOW` protection.

For the `pdm.toml` PoC specifically, the target file must already contain parseable TOML. Otherwise the load step fails before the write path is reached. That parser constraint does not apply to the `.pdm-python` or `.python-version` sinks.

## Impact

- Arbitrary file clobber as the invoking user - Destructive modification of local files outside the repository root - Useful primitive for privilege abuse when `pdm` is run in elev…