CVE-2026-27948: Copyparty vulnerable to eflected cross-site scripting via setck parameter
Summary An XSS allows for reflected cross-site scripting via URL-parameter ?setck=...
Details A reflected cross-site scripting (XSS) vulnerability could allow an attacker to execute malicious javascript by tricking users into accessing a malicious link.
The worst-case outcome of this is being able to move or delete existing files on the server, or upload new files, using the account of the person who clicks the malicious link.
Indicators of Compromise All attempted attacks (successful or not) would be logged to both the copyparty serverlog and the accesslog of the reverseproxy, and are detected by grep -E '[?&]setck=[^&"]%' (the text setck= eventually followed by the % character).
Other sources
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.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-27948?
CVE-2026-27948 is classified as a reflected cross-site scripting (XSS) vulnerability.
How do I fix CVE-2026-27948?
To fix CVE-2026-27948, upgrade to Copyparty version 1.20.9 or later.
What software is affected by CVE-2026-27948?
CVE-2026-27948 affects Copyparty versions prior to 1.20.9.
How can an attacker exploit CVE-2026-27948?
An attacker can exploit CVE-2026-27948 by tricking users into clicking a crafted link that includes a malicious URL parameter.
What is reflected cross-site scripting in the context of CVE-2026-27948?
Reflected cross-site scripting in CVE-2026-27948 allows an attacker to execute malicious JavaScript in a user's browser through a URL with a vulnerable parameter.