CVE-2026-6357 pip self-update functionality can import newly installed modules after wheel installation
Attackers can execute arbitrary code by installing malicious wheels that are imported during pip's self-update check before the update completes.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-6357?
CVE-2026-6357 is a medium-severity code injection vulnerability in pip, published on 27 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-829
Which versions are affected by CVE-2026-6357?
3 open source packages ship an affected version, including pip.
| Package | Affected | Fixed in |
|---|---|---|
pip PyPI | All versions | 26.1 |
pip PyPI | All versions | 26.1 |
pip PyPI | All versions | 26.1 |
How do I fix CVE-2026-6357?
Upgrade pip to 26.1 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-6357 being exploited?
There is no known exploitation of CVE-2026-6357 in the wild and no public exploit code.
Sources
Also known as AZL-85011, AZL-85265, BELL-CVE-2026-6357, CLEANSTART-2026-SE54902, CLEANSTART-2026-ZI04041, DEBIAN-CVE-2026-6357 and 14 more.