{"id":"CVE-2026-113726","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-113726","generatedAt":"2026-10-28T07:41:54.895Z","title":"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.","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.","published":"2026-10-20T22:19:29.000Z","lastModified":"2026-10-27T22:17:23.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},"cwe":["CWE-78","CWE-116"],"affected":[],"epss":{"score":0.00263,"percentile":0.18025,"date":"2026-10-27","history":[{"date":"2026-10-21","score":0.00234,"percentile":0.13519}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-20T22:19:29.000Z","detail":{"score":"7.8","severity":"HIGH","publishedAt":"2026-10-20T22:19:29.423Z"},"summary":"New CVE, high severity (CVSS 7.8)."}],"references":[{"url":"https://github.com/pypa/virtualenv/commit/5b915367da82bd024b2a0d28d2f98007034b4aa2","source":"security-advisories@github.com"},{"url":"https://github.com/pypa/virtualenv/releases/tag/21.14.4","source":"security-advisories@github.com"},{"url":"https://github.com/pypa/virtualenv/security/advisories/GHSA-5vjq-rrrf-7h2q","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-113726","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}