Threats affecting pkg:brew/hatch

A vulnerability in virtualenv's xonsh activation script allows attacker-controlled prompt text to become executable code during environment activation if the xonsh source encoding is a legacy multibyte encoding such as GBK or Big5. This occurs because the activation script is written in UTF-8 but read with a different codec, causing misinterpretation of escape sequences and enabling code injection. The issue affects POSIX activation scripts and requires an attacker to control the prompt or destination argument passed to virtualenv, with the user subsequently activating the environment. The vulnerability is fixed in virtualenv version 1.18.1_2.

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 virtualenv installs without verifying its integrity. Both --seeder pip and --download options must be enabled for exploitation. A fix is available in virtualenv version 1.18.1_2.

CVE-2026-113714 is a vulnerability in virtualenv's wheel download and caching mechanism where downloaded wheel files are placed directly into the reusable wheel cache before verification. The verification process selects the file to check based on pip's textual output rather than the actual downloaded file, allowing an attacker-controlled package index to inject forged output lines. This can cause a modified wheel to be cached and reused despite failing verification, potentially leading to the use of tampered packages in new environments. The issue does not bypass TLS or affect the default PyPI setup and requires a custom index with digest verification enabled. A fix was released in virtualenv version 1.18.1_2 that downloads wheels to a temporary location and only promotes them to the cache after successful verification.