CVE-2026-113726
virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST
Impact
virtualenv is a tool for creating isolated virtual python environments. Prior to 21.13.0, the bash activate script that zsh also sources leaves the environment name unescaped; from 21.13.0 until 21.14.4, it escapes backslashes, dollar signs, and backticks only when BASH_VERSION is set, so zsh receives the raw value. The script assigns that value to PS1. In zsh with PROMPT_SUBST, an attacker-influenced environment directory, --prompt, or VIRTUALENV_PROMPT value containing command, parameter, or arithmetic expansion syntax can therefore execute commands in the user's shell each time the prompt is drawn. A percent sign is separately interpreted as a zsh prompt escape but does not by itself execute commands. Plain zsh with PROMPT_SUBST disabled and bash are not affected by this mechanism. This issue is fixed in version 21.14.4.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | virtualenv | <= 21.14.3 | 21.14.4 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-5vjq-rrrf-7h2q
- https://github.com/pypa/virtualenv/security/advisories/GHSA-5vjq-rrrf-7h2q
- https://nvd.nist.gov/vuln/detail/CVE-2026-113726
- https://github.com/pypa/virtualenv/commit/5b915367da82bd024b2a0d28d2f98007034b4aa2
- https://github.com/pypa/virtualenv/releases/tag/21.14.4