CVE-2026-104102
Deferred Deferred - Pending Action

Path Traversal in copyparty File Server

Publication date: 2026-10-12

Last updated on: 2026-10-12

Assigner: GitHub, Inc.

Description
copyparty is a portable file server. Prior to 1.20.19, FTP upload path handling does not confine destinations to configured copyparty volumes. When FTP or FTPS is explicitly enabled, a low-privileged authenticated user can submit traversal paths during upload to create a new file outside configured volumes wherever the copyparty process has write permission. The attacker cannot read or overwrite files, the output name receives a randomized suffix, and copyparty does not execute the file; however, unrelated software on the same host could process the newly created file. This issue is fixed in version 1.20.19.

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Meta Information

Published
2026-10-12
Last Modified
2026-10-12
Generated
2026-10-13
AI Q&A
2026-10-12
EPSS Evaluated
N/A
NVD
CVE-2026-104102
EUVD
EUVD-2026-97760

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
9001 copyparty < 1.20.19

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Exploitability

CWE
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KEV
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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.

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Executive Summary

CVE-2026-104102 is a vulnerability in copyparty, a portable file server. It affects FTP and FTPS uploads in versions before 1.20.19. The issue allows authenticated users to upload files outside configured volumes by using path traversal sequences. The copyparty process must have write permissions in the target directory. Uploaded files receive randomized names, preventing overwrites or appends, and the server does not execute them.

Detection Guidance

Check if copyparty is running with FTP or FTPS enabled by inspecting process logs or configuration files. Look for unauthorized file uploads in directories outside configured volumes. Verify copyparty version is 1.20.19 or later.

Impact Analysis

An attacker could create files in directories outside copyparty's intended scope. While the attacker cannot read or overwrite existing files, other software on the same host might process these new files. This could lead to unintended behavior or further exploitation if the uploaded files are executed by other services.

Compliance Impact

This vulnerability could potentially impact compliance with GDPR and HIPAA by allowing unauthorized file creation outside configured volumes. If exploited, it may lead to unintended data exposure or processing of sensitive files by unrelated software, violating data protection requirements.

Mitigation Strategies

Upgrade copyparty to version 1.20.19 or later. Disable FTP and FTPS if not needed. Restrict filesystem permissions for the copyparty process to limit write access.

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