What’s Vulnerable › Vulnerabilities

CVE-2026-6357: pip self-update functionality can import newly installed modules after wheel installation

• Severity: medium (CVSS 5.3 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-27 · updated 2026-06-17
• Weakness: CWE-829

Description

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.

Affected products

• Pypi Pip: before 26.1; 0.2, 0.2.1, 0.3, 0.3.1, 0.4, 0.5 (+148) — fixed in 26.1
• Python Packaging Authority pip: before 26.1 — fixed in 26.1

How to fix

Upgrade to a fixed version: Pypi Pip 26.1; Python Packaging Authority pip 26.1. Check the vendor advisory for mitigations.

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

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