CVE-2026-59890: setuptools: MANIFEST.in exclusion bypass in sdist via Unicode normalization collision (NFC/NFD) on macOS APFS/HFS+

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-07-08 · updated 2026-10-25
Weakness: CWE-176

Description

setuptools is a package that allows users to download, build, install, upgrade, and uninstall Python packages. Prior to 83.0.0, FileList applied MANIFEST.in exclude, global-exclude, recursive-exclude, and prune directives by matching compiled glob patterns against on-disk file names without Unicode normalization, so on macOS APFS or HFS+ an NFD file name could bypass an NFC exclusion rule and be packed into a source distribution. This issue is fixed in version 83.0.0.

Affected products

pypa setuptools: before 83.0.0 — fixed in 83.0.0
Pypi Setuptools: before 83.0.0; 0.6b1, 0.6b2, 0.6b3, 0.6b4, 0.6c1, 0.6c10 (+494) — fixed in 83.0.0

How to fix

Upgrade to a fixed version: pypa setuptools 83.0.0; Pypi Setuptools 83.0.0. Check the vendor advisory for mitigations.

References

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