# CVE-2026-113717: virtualenv verification bypass in wheel download and seeding

Source: https://junglewise.ai/threats/cve-2026-113717-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-2026-113717 · Severity: medium · CVSS 4 · Published 2026-10-20

virtualenv is a tool that creates isolated Python environments for safe package management. Prior to version 21.14.9, the pip seeder could bypass SHA-256 digest verification from PyPI, potentially allowing installation of unverified or counterfeit packages from package indexes. An attacker controlling a non-PyPI index could exploit this to inject malicious packages into environments that rely on the default verification settings.

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-2026-113717 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-113717 being exploited in the wild.

**How severe is CVE-2026-113717?** Medium severity, with a CVSS score of 4, published 20 October 2026.

**Which products and versions are affected?** Pypa Virtualenv before 21.14.9; virtualenv (PyPI) < 21.14.9, ECOSYSTEM:introduced=0,fixed=21.14.9.

**Is there a fix for CVE-2026-113717?** Yes. virtualenv (PyPI): upgrade to 21.14.9 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-113717 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-113717?** 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 21.14.9 or later

  ```sh
  pip install "virtualenv>=21.14.9"
  ```


## Technical details

The vulnerability exists in PipInvoke.get_pip_install_cmd() and download_wheel(): when using --seeder pip --download, the code called get_wheel(download=False) and allowed pip to consult the configured index without verifying the resulting wheel against PyPI's published SHA-256 digest. The pip seeder also performed its own index lookup outside the verification path. The fix ensures all downloads land in a private staging directory, pass cryptographic checks against PyPI metadata (when using the default index), and only then move into the reusable cache; pip installs only from that verified set with the index disabled.

## Affected products

- pypa virtualenv before 21.14.9

## Identifiers

- CVE-2026-113717
- GHSA-cx28-75q4-x26q

## Timeline

- 2026-10-17: patched
- 2026-10-20: advisory

## References

- [https://github.com/pypa/virtualenv/commit/7babec66e043e1cc8bc66869a063653898719d96](https://github.com/pypa/virtualenv/commit/7babec66e043e1cc8bc66869a063653898719d96)
- [https://github.com/pypa/virtualenv/pull/3430](https://github.com/pypa/virtualenv/pull/3430)

## 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)
- [virtualenv command injection in Fish shell activation script](https://junglewise.ai/threats/cve-2026-113732-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)