Path Traversal in Microsoft Windows
CVE-2026-3087
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.007 (53.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.002
Affected products
- Microsoft Windows
- Python — versions 3.15.0
- Python Software Foundation Cpython — versions 0, 3.13.0, 3.11.0
Weakness classification (CWE)
References
- github.com/python/cpython/pull/146591 (Patch, patch, Issue Tracking)
- github.com/python/cpython/issues/146581 (issue-tracking, Exploit, Patch, Issue Tracking, Vendor Advisory)
- mail.python.org/archives/list/security-announce@python.org/thread/X6FXE5C6KDKOV… (vendor-advisory, Mailing List, Vendor Advisory)
- github.com/python/cpython/commit/ab5ef98af693bded74a738570e81ea70abef2840 (Patch, patch)
- github.com/python/cpython/commit/b01e594fbe754a960212f908d047294e880b52fd (Patch, patch)
- github.com/python/cpython/commit/fc829e88753858c8ac669594bf0093f44948c0f4 (Patch, patch)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
- github.com/python/cpython/commit/65b255416ae217bf0e22085be3c1976cea18bd8c (Patch, patch)
- github.com/python/cpython/commit/8e13025747e1ca72e86d1f35637123f9c306f0cb (Patch, patch)
- github.com/python/cpython/commit/8ee6aff14054b37b53e47194a2fa313e98163c94 (Patch, patch)
Frequently asked questions
- What is CVE-2026-3087?
- CVE-2026-3087 is a high-severity vulnerability in Microsoft Windows, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-04-27.
- How severe is CVE-2026-3087?
- High severity. CVSS v3 base score is 7.5 out of 10.