Summary
virtualenv: Downloaded seed wheels (pip/setuptools) are not integrity-checked before use
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
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-102930? CVE-2026-102930 is a high-severity security vulnerability in virtualenv (pip), affecting versions <= 21.7.11. It is fixed in 21.7.12.
- Which versions of virtualenv are affected by CVE-2026-102930? virtualenv (pip) versions <= 21.7.11 is affected.
- Is there a fix for CVE-2026-102930? Yes. CVE-2026-102930 is fixed in 21.7.12. Upgrade to this version or later.
- Is CVE-2026-102930 exploitable, and should I be worried? Whether CVE-2026-102930 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-102930 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-102930? Upgrade
virtualenvto 21.7.12 or later.