CVE-2026-3087 shutil.unpack_archive() doesn't check for Windows absolute paths in ZIPs

What is CVE-2026-3087?

CVE-2026-3087 is a medium-severity path traversal vulnerability in Python Python, published on 27 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

If `shutil.unpack_archive()` is given a ZIP archive with an absolute Windows path containing a drive (`C:\\...`) then the archive will be extracted outside the target directory which is different than other operating systems. Only Windows is affected by this vulnerability.

Weakness: CWE-22

Which versions are affected by CVE-2026-3087?

3 open source packages ship an affected version, including libpython, python and python-min. It affects 1 product.

Products include Python Python.

How do I fix CVE-2026-3087?

Upgrade libpython to a fixed version for your release line: 3.10.21, 3.11.16, 3.12.14 or 3.13.14.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-3087 being exploited?

There is no known exploitation of CVE-2026-3087 in the wild and no public exploit code.

Other vulnerabilities in Python Python

• CVE-2008-5031 Integer overflow in n/a Critical 10.0
• CVE-2014-4650 Path traversal in n/a Critical 9.8
• CVE-2016-5636 Integer overflow in n/a Critical 9.8
• CVE-2007-4559 Path traversal in n/a Critical 9.8
• CVE-2017-17522 Command injection in n/a High 8.8

All Python Python vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-85274, BIT-libpython-2026-3087, BIT-python-2026-3087, BIT-python-min-2026-3087, GHSA-7r27-jhmm-vmp6, MINI-4gj2-v85m-7mgj and 5 more.