Affected: Bitnami: virtualenv

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, PipInstall._uninstall_previous_version() accepts existing seed-package metadata and _uninstall_dist() joins entries from top_level.txt and RECORD to site-packages without checking containment. When a reused destination contains distribution metadata influenced by another account, relative traversal, absolute entries, or linked parents can cause app-data reseeding to delete files outside the environment or the environment root with the invoking user's permissions, provided that user has deletion rights over the named paths. The deletion occurs during environment creation before any later use of the environment. Fresh environments without existing package metadata and creation with --clear do not enter this cleanup path. This issue is fixed in version 21.14.9.

Affected: pypa virtualenv

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, PipInstall._uninstall_previous_version() accepts existing seed-package metadata and _uninstall_dist() joins entries from top_level.txt and RECORD to site-packages without checking containment. When a reused destination contains distribution metadata influenced by another account, relative traversal, absolute entries, or linked parents can cause app-data reseeding to delete files outside the environment or the environment root with the invoking user's permissions, provided that user has deletion rights over the named paths. The deletion occurs during environment creation before any later use of the environment. Fresh environments without existing package metadata and creation with --clear do not enter this cleanup path. This issue is fixed in version 21.14.9.

Affected: PyPI: virtualenv

## Summary

The app-data seeder joins paths from existing distribution metadata to site-packages and deletes the resulting paths without checking containment within the environment.

Anthropic's OSS Scanner reported this as `ANT-2026-SXOEHWP7` in `virtualenv-20261015-005`, received on 15 October 2026.

## Affected area

Removal of a previously installed seed package.

## Attacker-controlled input

An environment being reused must contain distribution metadata influenced by another account. The invoking user must have deletion rights over the paths named by that metadata. Installing a new environment without existing package metadata does not enter this cleanup path.

## Affected code

The relevant 21.14.8 source is in [seed uninstall](https://github.com/pypa/virtualenv/blob/a795ab116356afde11039cf2763d77e8a06da738/src/virtualenv/seed/embed/via_app_data/pip_install/base.py).

## Mechanism

Before reinstalling a seed wheel, `PipInstall._uninstall_previous_version()` accepts an existing `pip-*.dist-info` directory in the destination. `_uninstall_dist()` reads its `top_level.txt` and `RECORD`, joins each entry to `site-packages`, and deletes the result. It does not check whether `..`, an absolute entry, or a linked parent takes the path outside the environment. The default app-data seeder reaches this path when it reuses a tree containing seed-package metadata; `--clear` removes that tree first.

## Reproduction and evidence

The scanner prepared a project with `.venv/lib/python…