id: PYSEC-2026-1278
published: "2026-07-07T14:34:50.251716Z"
modified: "2026-07-07T17:23:57.865589Z"
aliases:
- CVE-2025-27145
- GHSA-m2jw-cj8v-937r
summary: copyparty renders unsanitized filenames as HTML when user uploads empty files
details: "## Summary\n\nA [DOM-Based XSS](https://capec.mitre.org/data/definitions/588.html) was discovered in [copyparty](https://github.com/9001/copyparty), a portable fileserver. The vulnerability is considered low-risk.\n\n## Details\n\nBy handing someone a maliciously-named file, and then tricking them into dragging the file into copyparty's Web-UI, an attacker could execute arbitrary javascript with the same privileges as that user. For example, this could give unintended read-access to files owned by that user. The bug is triggered by the drag-drop action itself; it is not necessary to actually initiate the upload. The file must be empty (zero bytes).\n\nNote: As a general-purpose webserver, it is intentionally possible to upload HTML-files with arbitrary javascript in `<script>` tags, which will execute when the file is opened. The difference is that this vulnerability would trigger execution of javascript during the act of uploading, and not when the uploaded file was opened.\n\n## Proof of Concept (POC)\n\n1. Create an empty file named `<img src=x onerror=\"alert(1)\">`\n2. Drag-and-drop the file into the browser to initiate an upload\n3. The `alert(1)` is executed"
affected:
- package:
    name: copyparty
    ecosystem: PyPI
    purl: pkg:pypi/copyparty
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 1.16.15
  versions:
  - 0.10.0
  - 0.10.1
  - 0.10.10
  - 0.10.11
  - 0.10.12
  - 0.10.13
  - 0.10.14
  - 0.10.15
  - 0.10.16
  - 0.10.17
  - 0.10.18
  - 0.10.19
  - 0.10.2
  - 0.10.20
  - 0.10.21
  - 0.10.22
  - 0.10.3
  - 0.10.4
  - 0.10.5
  - 0.10.6
  - 0.10.7
  - 0.10.8
  - 0.10.9
  - 0.11.0
  - 0.11.1
  - 0.11.10
  - 0.11.11
  - 0.11.12
  - 0.11.13
  - 0.11.14
  - 0.11.15
  - 0.11.16
  - 0.11.17
  - 0.11.18
  - 0.11.19
  - 0.11.20
  - 0.11.21
  - 0.11.22
  - 0.11.23
  - 0.11.24
  - 0.11.26
  - 0.11.27
  - 0.11.28
  - 0.11.29
  - 0.11.30
  - 0.11.31
  - 0.11.32
  - 0.11.33
  - 0.11.34
  - 0.11.35
  - 0.11.36
  - 0.11.37
  - 0.11.38
  - 0.11.39
  - 0.11.40
  - 0.11.41
  - 0.11.42
  - 0.11.43
  - 0.11.44
  - 0.11.45
  - 0.11.46
  - 0.11.47
  - 0.11.5
  - 0.11.6
  - 0.11.7
  - 0.11.8
  - 0.11.9
  - 0.12.1
  - 0.12.10
  - 0.12.11
  - 0.12.12
  - 0.12.3
  - 0.12.4
  - 0.12.5
  - 0.12.6
  - 0.12.7
  - 0.12.8
  - 0.12.9
  - 0.13.0
  - 0.13.1
  - 0.13.10
  - 0.13.11
  - 0.13.12
  - 0.13.13
  - 0.13.14
  - 0.13.2
  - 0.13.3
  - 0.13.5
  - 0.13.6
  - 0.13.7
  - 0.13.9
  - 0.2.3
  - 0.3.0
  - 0.3.1
  - 0.4.0
  - 0.4.1
  - 0.4.2
  - 0.4.3
  - 0.5.0
  - 0.5.1
  - 0.5.2
  - 0.5.3
  - 0.5.4
  - 0.5.5
  - 0.5.6
  - 0.5.7
  - 0.6.0
  - 0.6.2
  - 0.6.3
  - 0.7.0
  - 0.7.1
  - 0.7.2
  - 0.7.3
  - 0.7.4
  - 0.7.5
  - 0.7.6
  - 0.7.7
  - 0.8.1
  - 0.8.3
  - 0.9.0
  - 0.9.1
  - 0.9.10
  - 0.9.11
  - 0.9.13
  - 0.9.3
  - 0.9.4
  - 0.9.5
  - 0.9.6
  - 0.9.7
  - 0.9.8
  - 0.9.9
  - 1.0.0
  - 1.0.1
  - 1.0.10
  - 1.0.11
  - 1.0.12
  - 1.0.13
  - 1.0.14
  - 1.0.2
  - 1.0.3
  - 1.0.4
  - 1.0.5
  - 1.0.7
  - 1.0.8
  - 1.0.9
  - 1.1.0
  - 1.1.1
  - 1.1.10
  - 1.1.11
  - 1.1.12
  - 1.1.2
  - 1.1.3
  - 1.1.4
  - 1.1.5
  - 1.1.6
  - 1.1.7
  - 1.1.8
  - 1.1.9
  - 1.10.0
  - 1.10.1
  - 1.10.2
  - 1.11.0
  - 1.11.1
  - 1.11.2
  - 1.12.0
  - 1.12.1
  - 1.12.2
  - 1.13.0
  - 1.13.1
  - 1.13.2
  - 1.13.3
  - 1.13.4
  - 1.13.5
  - 1.13.6
  - 1.13.7
  - 1.13.8
  - 1.14.0
  - 1.14.1
  - 1.14.2
  - 1.14.3
  - 1.14.4
  - 1.15.0
  - 1.15.1
  - 1.15.10
  - 1.15.2
  - 1.15.3
  - 1.15.4
  - 1.15.5
  - 1.15.6
  - 1.15.7
  - 1.15.8
  - 1.15.9
  - 1.16.0
  - 1.16.1
  - 1.16.10
  - 1.16.11
  - 1.16.12
  - 1.16.13
  - 1.16.14
  - 1.16.2
  - 1.16.3
  - 1.16.4
  - 1.16.5
  - 1.16.6
  - 1.16.7
  - 1.16.8
  - 1.16.9
  - 1.2.0
  - 1.2.1
  - 1.2.10
  - 1.2.11
  - 1.2.2
  - 1.2.3
  - 1.2.4
  - 1.2.5
  - 1.2.6
  - 1.2.7
  - 1.2.8
  - 1.2.9
  - 1.3.0
  - 1.3.1
  - 1.3.10
  - 1.3.11
  - 1.3.12
  - 1.3.13
  - 1.3.14
  - 1.3.15
  - 1.3.16
  - 1.3.2
  - 1.3.3
  - 1.3.4
  - 1.3.5
  - 1.3.6
  - 1.3.7
  - 1.3.8
  - 1.3.9
  - 1.4.0
  - 1.4.1
  - 1.4.2
  - 1.4.3
  - 1.4.4
  - 1.4.5
  - 1.4.6
  - 1.5.0
  - 1.5.1
  - 1.5.2
  - 1.5.3
  - 1.5.4
  - 1.5.5
  - 1.5.6
  - 1.6.0
  - 1.6.1
  - 1.6.10
  - 1.6.11
  - 1.6.12
  - 1.6.13
  - 1.6.14
  - 1.6.15
  - 1.6.2
  - 1.6.3
  - 1.6.4
  - 1.6.5
  - 1.6.6
  - 1.6.7
  - 1.6.8
  - 1.6.9
  - 1.7.0
  - 1.7.1
  - 1.7.2
  - 1.7.3
  - 1.7.4
  - 1.7.5
  - 1.7.6
  - 1.8.0
  - 1.8.1
  - 1.8.2
  - 1.8.3
  - 1.8.4
  - 1.8.6
  - 1.8.7
  - 1.8.8
  - 1.9.0
  - 1.9.1
  - 1.9.10
  - 1.9.11
  - 1.9.12
  - 1.9.13
  - 1.9.14
  - 1.9.15
  - 1.9.16
  - 1.9.17
  - 1.9.18
  - 1.9.19
  - 1.9.2
  - 1.9.20
  - 1.9.21
  - 1.9.24
  - 1.9.25
  - 1.9.26
  - 1.9.27
  - 1.9.28
  - 1.9.29
  - 1.9.3
  - 1.9.30
  - 1.9.31
  - 1.9.4
  - 1.9.5
  - 1.9.6
  - 1.9.7
  - 1.9.8
  - 1.9.9
references:
- type: WEB
  url: https://github.com/9001/copyparty/security/advisories/GHSA-m2jw-cj8v-937r
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2025-27145
- type: WEB
  url: https://github.com/9001/copyparty/commit/438ea6ccb06f39d7cbb4b6ee7ad44606e21a63dd
- type: PACKAGE
  url: https://github.com/9001/copyparty
- type: WEB
  url: https://github.com/9001/copyparty/releases/tag/v1.16.15
- type: PACKAGE
  url: https://pypi.org/project/copyparty
- type: ADVISORY
  url: https://github.com/advisories/GHSA-m2jw-cj8v-937r
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N