{"cve":"CVE-2026-113726","nvd":{"published":"2026-10-20T22:19:29.423","modified":"2026-10-22T16:47:38.403","status":"Awaiting Analysis","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-78","CWE-116"],"references":["https://github.com/pypa/virtualenv/commit/5b915367da82bd024b2a0d28d2f98007034b4aa2","https://github.com/pypa/virtualenv/releases/tag/21.14.4","https://github.com/pypa/virtualenv/security/advisories/GHSA-5vjq-rrrf-7h2q"],"products":[],"source":"nvd","synced_at":"2026-10-23T16:39:26.291718493+00:00"},"epss":{"cve":"CVE-2026-113726","score":0.00263,"percentile":0.17948,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-5vjq-rrrf-7h2q","url":"https://osv.dev/vulnerability/GHSA-5vjq-rrrf-7h2q","summary":"virtualenv activate runs commands from the environment name in zsh with PROMPT_SUBST","modified":"2026-10-21T17:00:06.164317431Z","packages":[{"ecosystem":"PyPI","name":"virtualenv","purl":"pkg:pypi/virtualenv","ranges":["<21.14.4"],"fixed":["21.14.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}