---
id: CVE-2026-113716
title: 'virtualenv: Builtin creation follows linked environment directories'
summary: >-
  virtualenv is a tool for creating isolated virtual python environments. Prior
  to 21.14.9, the builtin creator calls ensure_dir() for executable, library,
  and package directories, and ensure_dir() accepts an existing symlink to a
  director…
severity: medium
cvss: 4.5
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-59
vendor: pypa
product: virtualenv
affected:
  - virtualenv < 21.14.9
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T19:18:09.392Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-113716'
references:
  - url: 'https://github.com/pypa/virtualenv/security/advisories/GHSA-cw65-gx24-rc82'
    label: 'https://github.com/pypa/virtualenv/security/advisories/GHSA-cw65-gx24-rc82'
  - url: 'https://github.com/pypa/virtualenv/pull/3429'
    label: 'https://github.com/pypa/virtualenv/pull/3429'
  - url: >-
      https://github.com/pypa/virtualenv/commit/554d9f9d4f7758f5cf53f993031e29787f1f74c5
    label: >-
      https://github.com/pypa/virtualenv/commit/554d9f9d4f7758f5cf53f993031e29787f1f74c5
  - url: 'https://github.com/pypa/virtualenv/releases/tag/21.14.9'
    label: 'https://github.com/pypa/virtualenv/releases/tag/21.14.9'
tags:
  - cve.org
ingestedAt: '2026-10-20T20:18:14.542Z'
---

## Overview

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, the builtin creator calls ensure_dir() for executable, library, and package directories, and ensure_dir() accepts an existing symlink to a directory because exists() follows it. Interpreter creation, seed installation, and activation generation then write through the linked parent outside the requested destination when another local account prepared the tree and the invoking user can access the target. The --clear option removes the planted tree first, while ordinary creation reaches it; arbitrary attacker-selected output bytes are not established. This issue is fixed in version 21.14.9.

## Affected

- `virtualenv < 21.14.9`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.