CVE-2026-27948: Copyparty vulnerable to eflected cross-site scripting via setck parameter

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-26 · updated 2026-06-17
Weakness: CWE-79

Description

Copyparty is a portable file server. In versions prior to 1.20.9, an XSS allows for reflected cross-site scripting via URL-parameter `?setck=...`. Version 1.20.9 fixes the issue.

Affected products

9001 copyparty: before 1.20.9 — fixed in 1.20.9

How to fix

Upgrade to a fixed version: 9001 copyparty 1.20.9. Check the vendor advisory for mitigations.

References

https://github.com/9001/copyparty/commit/31b2801fd041f803f4a3d5c12c7d7cb5419048bc
https://github.com/9001/copyparty/security/advisories/GHSA-62cr-6wp5-q43h

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