Microsoft Security Response Center guidance
Vendor revision: Nov 4, 2026Release Notes
Vulnerability intelligence
CVE-2026-113714 and is rated Low severity with a CVSS score of 2.3. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
virtualenv is a tool for creating isolated virtual python environments. Prior to 21.14.9, download_wheel() writes package-index downloads directly into the reusable wheel/house cache before selecting a verification target from pip's textual Saved output.
With default-index digest comparison enabled, a controlled package index can inject a misleading Saved line through a discarded link's data-requires-python attribute; this forged-line variant also requires knowledge of an absolute path to the genuine bundled wheel. The wrong path can then be hashed, while a digest mismatch leaves the rejected archive in the cache for later selection without verification.
A separate rejected-cache-file variant requires control over downloaded data or archive selection but not the forged-line prerequisites. Explicit custom-index exceptions are outside the promised PyPI comparison, and the issue does not independently bypass TLS or establish control of default PyPI.
This issue is fixed in version 21.14.9.
Source: NVD