CVE-2026-102930: virtualenv Downloaded Seed Wheels (pip/setuptools) Are Vulnerability

HIGH
Advisory Identifier: GHSA-94p9-xgh2-xp45
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CWE-494
Published
Advisory Summary

CVE-2026-102930 is a HIGH downloaded seed wheels (pip/setuptools) are vulnerability (CWE-494: Download of Code Without Integrity Check) affecting virtualenv libraries in the PyPI ecosystem. The issue involves downloaded seed wheels (pip/setuptools) are not integrity-checked before use. Remediation is available by upgrading affected packages to version 21.7.12.

CVE-2026-102930 at a Glance

CVE Identifier CVE-2026-102930
GHSA Identifier GHSA-94p9-xgh2-xp45
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-494: Download of Code Without Integrity Check
Affected Product virtualenv
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-102930

To remediate this vulnerability, upgrade all affected virtualenv dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

virtualenv fixed: 21.7.12 
pip install virtualenv>=21.7.12
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show virtualenv

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-102930, inspect your installed packages using pip:

pip show virtualenv

Analyze the terminal output to locate any version of virtualenv in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 21.7.12), your application is affected.

Note: The pip show virtualenv command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-494: Download of Code Without Integrity Check, where the product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code. In virtualenv, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

`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

CVE-2026-102930 Affected virtualenv Versions

1 component(s)
Fixed Versions:
21.7.12
Product / Package Ecosystem Affected Versions Fixed Version
virtualenv
pypi/virtualenv
PyPI
< 21.7.12
21.7.12

References

GitHub Advisory / Wiki ADVISORY
https://github.com/pypa/virtualenv/security/advisories/GHSA-94p9-xgh2-xp45
NVD — CVE-2026-102930 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-102930
virtualenv Source Repository REPOSITORY
https://github.com/pypa/virtualenv/pull/3251
Security Fix Commit FIX COMMIT
https://github.com/pypa/virtualenv/commit/a01ed3e2f239d6ab1fce62c5c7664ccf268fff6d
virtualenv Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/virtualenv/PYSEC-2026-4011.yaml
virtualenv Source Repository REPOSITORY
https://github.com/pypa/virtualenv
virtualenv Release RELEASE
https://github.com/pypa/virtualenv/releases/tag/21.7.12
pypi.org/project/virtualenv WEB
https://pypi.org/project/virtualenv

Frequently Asked Questions

What is CVE-2026-102930?
CVE-2026-102930 is a security vulnerability in virtualenv involving Downloaded seed wheels (pip/setuptools) are not integrity-checked before use under CWE-494: Download of Code Without Integrity Check.
Which virtualenv versions are affected?
Affected versions include releases prior to 21.7.12 across affected packages: virtualenv.
What version fixes CVE-2026-102930?
Upgrading to 21.7.12 (or the latest patched release for your respective branch) resolves the vulnerability.
Is virtualenv affected?
Yes, virtualenv is affected in releases prior to 21.7.12. Upgrade your dependency to 21.7.12 or later.
What CWE is associated with CVE-2026-102930?
CVE-2026-102930 is classified under CWE-494: Download of Code Without Integrity Check (The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.).
How can I check PyPI dependencies for CVE-2026-102930?
Run the dependency tree command: 'pip show virtualenv'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-94p9-xgh2-xp45",
  "modified" : "2026-09-30T23:54:13Z",
  "published" : "2026-09-30T23:54:13Z",
  "aliases" : [ "CVE-2026-102930" ],
  "summary" : "virtualenv: Downloaded seed wheels (pip/setuptools) are not integrity-checked before use",
  "details" : "`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.\n\nA 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.\n\nFixed 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",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "virtualenv"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "21.7.12"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 21.7.11"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/security/advisories/GHSA-94p9-xgh2-xp45"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-102930"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/pull/3251"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/commit/a01ed3e2f239d6ab1fce62c5c7664ccf268fff6d"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/virtualenv/PYSEC-2026-4011.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pypa/virtualenv"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/virtualenv/releases/tag/21.7.12"
  }, {
    "type" : "WEB",
    "url" : "https://pypi.org/project/virtualenv"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-494" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-30T23:54:13Z",
    "nvd_published_at" : "2026-09-29T21:17:18Z"
  }
}