CVE-2026-59890: CWE-176: Improper Handling of Unicode Encoding in pypa setuptools
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.
AI Analysis
Technical Summary
The setuptools package, used for managing Python package distribution, had a flaw in versions before 83.0.0 where the FileList component applied MANIFEST.in exclusion directives by matching compiled glob patterns against on-disk file names without performing Unicode normalization. On macOS file systems such as APFS or HFS+, file names stored in Normalization Form D (NFD) could bypass exclusion rules written in Normalization Form C (NFC), allowing files intended to be excluded to be included in source distributions. This improper handling of Unicode encoding is classified under CWE-176 and CWE-697. The vulnerability is resolved in setuptools version 83.0.0.
Potential Impact
This vulnerability can lead to unintended files being included in Python source distributions when using setuptools on macOS systems with APFS or HFS+ file systems. This may expose sensitive or unwanted files in distributed packages, potentially leading to confidentiality breaches. The CVSS score is 6.1 (medium severity), indicating a moderate impact primarily on confidentiality with limited integrity impact and no availability impact.
Mitigation Recommendations
Upgrade setuptools to version 83.0.0 or later, where this Unicode normalization issue is fixed. No other mitigations are indicated. Patch status is confirmed by the vendor stating the issue is fixed in version 83.0.0.
CVE-2026-59890: CWE-176: Improper Handling of Unicode Encoding in pypa setuptools
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.
CVSS v3.1
Score 6.1medium
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The setuptools package, used for managing Python package distribution, had a flaw in versions before 83.0.0 where the FileList component applied MANIFEST.in exclusion directives by matching compiled glob patterns against on-disk file names without performing Unicode normalization. On macOS file systems such as APFS or HFS+, file names stored in Normalization Form D (NFD) could bypass exclusion rules written in Normalization Form C (NFC), allowing files intended to be excluded to be included in source distributions. This improper handling of Unicode encoding is classified under CWE-176 and CWE-697. The vulnerability is resolved in setuptools version 83.0.0.
Potential Impact
This vulnerability can lead to unintended files being included in Python source distributions when using setuptools on macOS systems with APFS or HFS+ file systems. This may expose sensitive or unwanted files in distributed packages, potentially leading to confidentiality breaches. The CVSS score is 6.1 (medium severity), indicating a moderate impact primarily on confidentiality with limited integrity impact and no availability impact.
Mitigation Recommendations
Upgrade setuptools to version 83.0.0 or later, where this Unicode normalization issue is fixed. No other mitigations are indicated. Patch status is confirmed by the vendor stating the issue is fixed in version 83.0.0.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-07T16:40:07.983Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e7ad4c9d9e3dbe36a7d68
Added to database: 07/08/2026, 16:29:08 UTC
Last enriched: 07/08/2026, 16:44:19 UTC
Last updated: 07/09/2026, 00:29:37 UTC
Views: 8
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