Vulnerability Description
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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/pypa/virtualenv/commit/5b915367da82bd024b2a0d28d2f98007034b4a
- https://github.com/pypa/virtualenv/releases/tag/21.14.4
- https://github.com/pypa/virtualenv/security/advisories/GHSA-5vjq-rrrf-7h2q
FAQ
What is CVE-2026-113726?
CVE-2026-113726 is a vulnerability with a CVSS score of 7.8 (HIGH). 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...
How severe is CVE-2026-113726?
CVE-2026-113726 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-113726?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.