# CVE-2026-113732: virtualenv command injection in Fish shell activation script

Source: https://junglewise.ai/threats/cve-2026-113732-virtualenv-is-a-tool-for-creating-isolated-virtual-python  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-113732 · Severity: high · CVSS 7.8 · Published 2026-10-20

virtualenv is a Python tool that creates isolated development environments. Prior to version 21.14.2, attackers can inject commands into the Fish shell activation script by embedding a backslash before a quote in a virtual environment path, --prompt argument, or environment variable. When users activate the virtual environment, malicious commands execute with their privileges.

Technologies: [Pypa Virtualenv](https://junglewise.ai/threats/technologies/pypa-virtualenv), [virtualenv (PyPI)](https://junglewise.ai/threats/technologies/virtualenv). Vendors: [Pypa](https://junglewise.ai/threats/vendors/pypa), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-113732 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-113732 being exploited in the wild.

**How severe is CVE-2026-113732?** High severity, with a CVSS score of 7.8, published 20 October 2026.

**Which products and versions are affected?** Pypa Virtualenv before 21.14.2; virtualenv (PyPI) <= 21.14.1, ECOSYSTEM:introduced=0,fixed=21.14.2.

**Is there a fix for CVE-2026-113732?** Yes. virtualenv (PyPI): upgrade to 21.14.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-113732 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-113732?** Check whether you run Pypa Virtualenv or virtualenv (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- virtualenv (PyPI): upgrade to 21.14.2 or later

  ```sh
  pip install "virtualenv>=21.14.2"
  ```


## Technical details

FishActivator used POSIX shlex.quote() to escape environment paths and prompts, but Fish shell interprets backslashes and single quotes differently than POSIX shells. An attacker-controlled path, --prompt, or VIRTUALENV_PROMPT value containing a backslash before a quote can terminate the generated shell literal and execute arbitrary command substitution when activate.fish is sourced. The fix adds Fish-specific quote escaping in FishActivator.

## Affected products

- pypa virtualenv before 21.14.2

## Identifiers

- CVE-2026-113732
- GHSA-c947-3pg5-gm8q

## Timeline

- 2026-10-20: disclosed: Published on NVD
- 2026-10-01: patched: Fixed in 21.14.2 release

## References

- [https://github.com/pypa/virtualenv/commit/3bddeaf8d02c3ee7f576503efb082f8f494cfcab](https://github.com/pypa/virtualenv/commit/3bddeaf8d02c3ee7f576503efb082f8f494cfcab)
- [https://github.com/pypa/virtualenv/releases/tag/21.14.2](https://github.com/pypa/virtualenv/releases/tag/21.14.2)

## Related threats

- [virtualenv bash activate command injection via unescaped prompt](https://junglewise.ai/threats/cve-2026-115586-virtualenv-is-a-tool-for-creating-isolated-virtual-python)
- [virtualenv command injection in activation script template substitution](https://junglewise.ai/threats/cve-2026-113776-virtualenv-is-a-tool-for-creating-isolated-virtual-python)
- [pypa virtualenv command injection in bash activate script](https://junglewise.ai/threats/cve-2026-113726-virtualenv-is-a-tool-for-creating-isolated-virtual-python)
- [virtualenv bash activate script command injection in PS1](https://junglewise.ai/threats/cve-2026-113725-virtualenv-is-a-tool-for-creating-isolated-virtual-python)
- [virtualenv safe_delete symlink mode change vulnerability](https://junglewise.ai/threats/cve-2026-113724-virtualenv-is-a-tool-for-creating-isolated-virtual-python)