CVE-2025-54423 copyparty has a DOM-Based XSS vulnerability when displaying multimedia metadata

What is CVE-2025-54423?

CVE-2025-54423 is a medium-severity cross-site scripting vulnerability in 9001 copyparty, published on 28 Jul 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

copyparty is a portable file server. In versions up to and including versions 1.18.4, an unauthenticated attacker is able to execute arbitrary JavaScript code in a victim's browser due to improper sanitization of multimedia tags in music files, including m3u files. This is fixed in version 1.18.5.

Weakness: CWE-79

Which versions are affected by CVE-2025-54423?

3 open source packages ship an affected version, including copyparty. It affects 1 product.

Products include 9001 Copyparty.

How do I fix CVE-2025-54423?

Upgrade copyparty to 1.18.5 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2025-54423 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-54423 exists.

Other vulnerabilities in 9001 copyparty

• CVE-2023-41471 Cross-site scripting in n/a High 7.8
• CVE-2025-54796 Copyparty is vulnerable to Regex Denial of Service (ReDoS) attacks through "Recent Uploads" page High 7.5
• CVE-2023-37474 Path traversal in copyparty High 7.5
• CVE-2025-54589 copyparty Reflected XSS via Filter Parameter Medium 6.3
• CVE-2023-38501 copyparty vulnerable to reflected cross-site scripting via k304 parameter Medium 6.3

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-9q4r-x2hj-jmvr, PYSEC-2026-1277.