Summary
copyparty FTP: upload outside defined volumes (limited path traversal)
The FTP and FTPS server -- if enabled -- would allow uploading to any folder that the copyparty process had permission to write to.
The FTP-server is default-disabled, and must be explicitly enabled in the config with global-option ftp or ftps to be affected. Additionally, SFTP was not affected at all; only FTP and FTPS.
This was not a full read/write path-traversal; it had the following limitations:
- Only applied to uploads; it was not possible to read/download existing files in this manner.
- The output filename was not fully controllable; a randomized suffix would always be appended to the filename.
- Existing files could not be overwritten or appended to; only new files could be created.
- Filesystem-permissions would prevent writing to system folders, as copyparty surely does not run as root in most deployments.
- Copyparty itself will not execute arbitrary files as code by default, so this vulnerability could not be used to execute arbitrary code through copyparty.
The main concern is the potential effect on other unrelated software which is running on the same system.
The severity is assuming the worst case (SC:H/SI:H), that the same machine is running some unrelated software that will execute new arbitrarily-named files as code, and that the copyparty process has sufficient privileges to write files into the config-folder of that unrelated software.
Impact
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-104102? CVE-2026-104102 is a medium-severity path traversal vulnerability in copyparty (pip), affecting versions < 1.20.19. It is fixed in 1.20.19. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- Which versions of copyparty are affected by CVE-2026-104102? copyparty (pip) versions < 1.20.19 is affected.
- Is there a fix for CVE-2026-104102? Yes. CVE-2026-104102 is fixed in 1.20.19. Upgrade to this version or later.
- Is CVE-2026-104102 exploitable, and should I be worried? Whether CVE-2026-104102 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-104102 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-104102? Upgrade
copypartyto 1.20.19 or later.