Mardi 20 octobre 2026

pypa virtualenv

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, PipInvoke.get_pip_install_cmd() handles --seeder pip --download by calling get_wheel(download=False) and then allowing pip to consult the configured index, bypassing virtualenv's download_wheel() and verify_wheel_digest() path. When virtualenv's default-index PyPI digest comparison remains enabled, an index candidate matching the bundled package and version can therefore be selected without comparison to PyPI SHA-256 metadata. Explicit custom-index settings already opt out of that comparison and remain outside this verification-bypass claim; the demonstrated configuration used a non-PyPI index while leaving the index environment variables unset so the comparison policy remained active. This condition does not independently defeat TLS or establish control of the index response. This issue is fixed in version 21.14.9.

pypa virtualenv

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, the stdlib venv creator reads generated pyvenv.cfg with str.splitlines() and merges parsed keys over virtualenv's selected configuration. An untrusted caller who influences the destination pathname can include a line-boundary character such as U+2028 to inject keys including home and include-system-site-packages, causing path data to change configuration structure before final output. Setting include-system-site-packages to true weakens environment isolation, while an altered home can change which standard-library files the interpreter loads if the attacker also controls that location. The builtin creator does not use this readback path. This issue is fixed in version 21.14.9.

pypa virtualenv

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, download_wheel() writes package-index downloads directly into the reusable wheel/house cache before selecting a verification target from pip's textual Saved output. With default-index digest comparison enabled, a controlled package index can inject a misleading Saved line through a discarded link's data-requires-python attribute; this forged-line variant also requires knowledge of an absolute path to the genuine bundled wheel. The wrong path can then be hashed, while a digest mismatch leaves the rejected archive in the cache for later selection without verification. A separate rejected-cache-file variant requires control over downloaded data or archive selection but not the forged-line prerequisites. Explicit custom-index exceptions are outside the promised PyPI comparison, and the issue does not independently bypass TLS or establish control of default PyPI. This issue is fixed in version 21.14.9.