Threats affecting pkg:brew/pipenv

A vulnerability in virtualenv's app-data copy seeder causes files copied from a cached wheel to retain file permissions from the cache, which may be more permissive than intended. This occurs because shutil.copy preserves the cached file modes regardless of the current umask. If the cache was created under a permissive umask (e.g., 000), files in later environments can be writable by other local accounts, potentially allowing unauthorized code modification and execution. The issue affects virtualenv versions from 2018.11.26_4 up to but not including 2026.10.1. A fix is available in version 2026.10.1 that enforces stricter file permissions when copying from the cache.

CVE-2026-113719 is a vulnerability in virtualenv's app-data seeder that improperly deletes files outside the intended environment during seed package removal. It occurs when existing distribution metadata contains paths that traverse outside the environment, allowing deletion of arbitrary files accessible by the invoking user. This affects virtualenv versions from 2021.11.9 up to but not including 2026.10.1. The issue was fixed in version 2026.10.1.

CVE-2026-113718 is a vulnerability in virtualenv's xonsh activation script where attacker-controlled prompt text can become executable code due to encoding mismatches. The issue arises when the activation script is read using legacy multibyte encodings like GBK or Big5 instead of UTF-8, causing backslash escapes to be misinterpreted and allowing injected code execution during environment activation. This affects POSIX xonsh activation scripts and requires an attacker to control the prompt or destination argument passed to virtualenv and a user to source the generated activation script. The vulnerability is fixed in virtualenv version 2026.10.1.

CVE-2026-113717 is a vulnerability in virtualenv's pip seeder when used with the --download option. The issue arises because the pip seeder downloads bundled wheels with download=False, skipping virtualenv's wheel digest verification. This allows an attacker controlling a package index to serve a modified pip wheel that bypasses the SHA-256 digest check, potentially installing tampered code. The vulnerability requires both the --seeder pip and --download options to be enabled. A fix is available in virtualenv version 2026.10.1.

A vulnerability in virtualenv's wheel download and caching mechanism allows a downloaded wheel to be cached before its integrity verification completes. An attacker controlling a package index can cause a mismatch between the downloaded file and the file verified by virtualenv, leading to reuse of unverified or tampered wheels from the cache. This issue affects virtualenv versions from 2026.8.0_1 up to but not including 2026.10.1 and was fixed in version 2026.10.1.

A vulnerability in virtualenv's venv creator allows attacker-controlled pathnames containing Unicode line boundary characters (e.g., U+2028) to inject additional configuration keys into the pyvenv.cfg file during configuration readback. This can alter environment settings such as the 'home' directory and 'include-system-site-packages', potentially changing which standard library files the interpreter loads and weakening environment isolation. The issue affects virtualenv versions from 2022.9.24 up to but not including 2026.10.1. A fix was introduced in version 2026.10.1 that rejects line-boundary characters before creation and rebuilds the configuration from selected settings.