CVE-2026-1703
Unknown Unknown - Not Provided
Path Traversal in pip Wheel Extraction Allows Directory Escape

Publication date: 2026-02-02

Last updated on: 2026-02-02

Assigner: Python Software Foundation

Description
When pip is installing and extracting a maliciously crafted wheel archive, files may be extracted outside the installation directory. The path traversal is limited to prefixes of the installation directory, thus isn't able to inject or overwrite executable files in typical situations.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-02-02
Last Modified
2026-02-02
Generated
2026-06-16
AI Q&A
2026-02-02
EPSS Evaluated
2026-06-15
NVD
CVE-2026-1703
EUVD
EUVD-2026-5106
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
pypa pip 26.0
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-22 The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

CVE-2026-1703 is a security vulnerability in the Python package installer pip where, during installation and extraction of a maliciously crafted wheel archive, files may be extracted outside the intended installation directory due to improper path prefix checking. The issue arises because pip used os.path.commonprefix(), which compares paths character-by-character and can be tricked by paths that share common prefixes but are not actually inside the directory. This could allow limited path traversal. The vulnerability was fixed by replacing commonprefix() with os.path.commonpath(), which compares path segments properly, preventing such traversal. [1, 2, 3]

Impact Analysis

This vulnerability can cause files from a malicious wheel archive to be extracted outside the intended installation directory during pip installation. Although the path traversal is limited to prefixes within the installation directory and does not typically allow injection or overwriting of executable files, it could still lead to unexpected file placement, potentially affecting system integrity or causing confusion in file management. [3]

Detection Guidance

This vulnerability can be detected by examining if pip versions prior to 26.0 are in use, as the issue was fixed in pip 26.0 by replacing `os.path.commonprefix()` with `os.path.commonpath()` to prevent path traversal during wheel extraction. To check your pip version, you can run the command `pip --version`. Additionally, inspecting wheel archives for malicious path traversal attempts would require custom scripts or tools to analyze wheel contents for paths that escape the intended installation directory, but no specific detection commands are provided in the resources. [1, 2]

Mitigation Strategies

The immediate mitigation step is to upgrade pip to version 26.0 or later, where the vulnerability has been fixed by using `os.path.commonpath()` for secure path validation during wheel extraction. This update was released on January 30, 2026, and includes the security fix along with other improvements. Avoid installing or extracting wheel archives from untrusted sources until the upgrade is applied. [1, 2, 3]

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-1703. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart