CVE-2026-6357

Weakness

pip prior to version 26.1 would run self-update check functionality after installing wheel files which required importing well-known Python modules names. These module imports were intentionally deferred to increase startup time of the pip CLI. The patch changes self-update functionality to run before wheels are installed to prevent newly-installed modules from being imported shortly after the installation of a wheel package. Users should still review package contents prior to installation.

References

• https://github.com/pypa/pip/pull/13923
• https://ichard26.github.io/blog/2026/04/whats-new-in-pip-26.1/#security-fixes
• http://www.openwall.com/lists/oss-security/2026/04/27/7