High

changedetection.io path traversal using file URI scheme without supplying hostname

  • Disclosed: 07.11.2024
  • Updated: 11.10.2026 13:19

Summary

The validation for the file URI scheme falls short, and results in an attacker being able to read any file on the system. This issue only affects instances with a webdriver enabled, and ALLOW_FILE_URI false or not defined.

Details

The check used for URL protocol, is_safe_url, allows file: as a URL scheme:

https://github.com/dgtlmoon/changedetection.io/blob/e0abf0b50507a8a3d0c1d8522ab23519b3e4cdf4/changedetectionio/model/Watch.py#L11-L13

It later checks if local files are permitted, but one of the preconditions for the check is that the URL starts with file://. The issue comes with the fact that the file URI scheme is not required to have double slashes.

A valid file URI must therefore begin with either file:/path (no hostname), file:///path (empty hostname), or file://hostname/path. — Wikipedia

https://github.com/dgtlmoon/changedetection.io/blob/e0abf0b50507a8a3d0c1d8522ab23519b3e4cdf4/changedetectionio/processors/__init__.py#L37-L41

PoC

  1. Open up a changedetection.io instance with a webdriver configured
  2. Create a new watch: file:/etc/passwd or a similar path for your operating system. Enable webdriver mode
  3. Wait for it to be checked
  4. Open preview
  5. Notice contents of the file

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) changedetection-io < 0.47.6 0.47.6

References

CVSS score 8.6/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Weakness (CWE)
CWE-22
Platform
Python (PyPI)
Package
changedetection-io
Disclosed
07.11.2024
Updated
11.10.2026 13:19

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-1239 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-6jrf-rcjf-245r - CC BY 4.0

Vulnerability history: changedetection-io

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (20) in the archive
Total entries
20
First → latest
02.2023 05.2026
Without a fix
1
Exploited in attacks
0

Severity breakdown

  • Critical 2
  • High 9
  • Medium 6
  • Low 2
  • Unrated 1

Disclosures per year

  1. 2023: 1
  2. 2024: 6
  3. 2025: 2
  4. 2026: 11
Severity:
  1. High · 7.5 CVE-2026-41895 <= 0.54.9 no fix
  2. High · 8.6 CVE-2026-27696 < 0.54.1 0.54.1
  3. High CVE-2025-52558 < 0.50.4 0.50.4
  4. changedetection.io path traversal using file URI scheme without supplying hostname this entry
    High · 8.6 CVE-2024-51998 < 0.47.6 0.47.6

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