All vulnerabilities
CVE-2026-102930BIT-virtualenv-2026-102930GHSA-94p9-xgh2-xp45PYSEC-2026-4011

virtualenv: Downloaded seed wheels (pip/setuptools) are not integrity-checked before use

pypa virtualenvpipLibraries & packages
Open in ThreatlineRecord JSON
CVSS
7.7High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.16%Chance of exploitation activity in the next 30 days, higher than 4% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in21.7.12Fixed versionGitHub
Published29 Sep 2026Updated 6 Oct 2026CVE List

What fixes it

  • 21.7.12virtualenv, pipGitHub
  • 21.7.12virtualenv, PyPIOSVpip install "virtualenv>=21.7.12"

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

download_wheel() runs pip download and hands the result straight to the seeder, with nothing checking the bytes it gets back. The embedded pip and setuptools wheels carry a BUNDLE_SHA256 that virtualenv checks on every load, but a wheel fetched over the network for the periodic-update feature or the --download flag had no equivalent verification.

A compromised index, a stale mirror, or a MITM'd download (when TLS is intercepted, e.g. via a misconfigured or malicious CA) could substitute a different wheel under the same distribution/version/filename, and virtualenv would cache and seed it into every environment created afterward with no warning.

Fixed by computing the downloaded wheel's sha256 and comparing it against the digest PyPI's public JSON API reports for that exact release, independent of which index actually served the file. The check is skipped, not treated as failure, when a custom index (PIP_INDEX_URL, PIP_EXTRA_INDEX_URL, PIP_INDEX) is configured, since a private index can legitimately serve a different, intentionally rebuilt wheel. Fix: https://github.com/pypa/virtualenv/pull/3251

Text from GitHub Advisory Database

Affected versions 53

  • virtualenv, pip<= 21.7.11GitHub
  • virtualenvaffected: < 21.7.12CVE List
  • virtualenv, PyPIfrom first release, fixed in 21.7.12OSV
  • virtualenv, PyPI0.8OSV
  • virtualenv, PyPI0.8.1OSV
  • virtualenv, PyPI0.8.2OSV
  • virtualenv, PyPI0.8.3OSV
  • virtualenv, PyPI0.8.4OSV
  • virtualenv, PyPI0.9OSV
  • virtualenv, PyPI0.9.1OSV
  • virtualenv, PyPI0.9.2OSV
  • virtualenv, PyPI1.0OSV
  • virtualenv, PyPI1.1OSV
  • virtualenv, PyPI1.10OSV
  • virtualenv, PyPI1.10.1OSV
  • virtualenv, PyPI1.11OSV
  • virtualenv, PyPI1.11.1OSV
  • virtualenv, PyPI1.11.2OSV
  • virtualenv, PyPI1.11.3OSV
  • virtualenv, PyPI1.11.4OSV
  • virtualenv, PyPI1.11.5OSV
  • virtualenv, PyPI1.11.6OSV
  • virtualenv, PyPI1.2OSV
  • virtualenv, PyPI1.3OSV
  • virtualenv, PyPI1.3.1OSV
  • virtualenv, PyPI1.3.2OSV
  • virtualenv, PyPI1.3.3OSV
  • virtualenv, PyPI1.3.4OSV
  • virtualenv, PyPI1.4OSV
  • virtualenv, PyPI1.4.1OSV
  • virtualenv, PyPI1.4.2OSV
  • virtualenv, PyPI1.4.3OSV
  • virtualenv, PyPI1.4.4OSV
  • virtualenv, PyPI1.4.5OSV
  • virtualenv, PyPI1.4.6OSV
  • virtualenv, PyPI1.4.7OSV
  • virtualenv, PyPI1.4.8OSV
  • virtualenv, PyPI1.4.9OSV
  • virtualenv, PyPI1.4rc1OSV
  • virtualenv, PyPI1.5OSV
  • virtualenv, PyPI1.5.1OSV
  • virtualenv, PyPI1.5.2OSV
  • virtualenv, PyPI1.6OSV
  • virtualenv, PyPI1.6.1OSV
  • virtualenv, PyPI1.6.2OSV
  • virtualenv, PyPI1.6.3OSV
  • virtualenv, PyPI1.6.4OSV
  • virtualenv, PyPI1.7OSV
  • virtualenv, PyPI1.7.1OSV
  • virtualenv, PyPI1.7.1.1OSV
  • virtualenv, PyPI1.7.1.2OSV
  • virtualenv, PyPI1.7.2OSV
  • virtualenv, PyPI1.8OSV

References 9