---
id: CVE-2026-113718
title: 'virtualenv: Xonsh activation literals depend on the script decoding codec'
summary: >-
  virtualenv is a tool for creating isolated virtual python environments. Prior
  to 21.14.9, POSIX xonsh activation quote() uses repr() to write printable
  non-ASCII prompt or destination data into UTF-8 activate.xsh, while xonsh can
  read th…
severity: high
cvss: 7.1
cvssVector: 'CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-94
vendor: pypa
product: virtualenv
affected:
  - virtualenv < 21.14.9
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T19:39:52.633Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-113718'
references:
  - url: 'https://github.com/pypa/virtualenv/security/advisories/GHSA-394h-qwmc-48pf'
    label: 'https://github.com/pypa/virtualenv/security/advisories/GHSA-394h-qwmc-48pf'
  - url: 'https://github.com/pypa/virtualenv/pull/3432'
    label: 'https://github.com/pypa/virtualenv/pull/3432'
  - url: >-
      https://github.com/pypa/virtualenv/commit/e5fc2e6e189a877ff559af288919e3525d13e5e0
    label: >-
      https://github.com/pypa/virtualenv/commit/e5fc2e6e189a877ff559af288919e3525d13e5e0
  - 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: '2026-10-20T20:18:14.532Z'
---

## Overview

virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, POSIX xonsh activation quote() uses repr() to write printable non-ASCII prompt or destination data into UTF-8 activate.xsh, while xonsh can read that script using $XONSH_ENCODING. Under a legacy multibyte codec such as GBK or Big5, a UTF-8 trail byte can consume the backslash before an adjacent quote, allowing the literal to close and attacker-influenced statements to execute when the user sources the generated script. 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.