CVE-2026-43891: changedetection.io Arbitrary Local File Read via Crafted Backup Restore
Summary
CVE-2026-43891: changedetection.io has an Arbitrary Local File Read via a crafted backup restore. Affects changedetection-io versions < 0.55.1. Fixed in 0.55.1. How to fix ↓
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Background
changedetection.io is an open-source web monitoring tool that allows users to track changes on websites. It provides functionalities such as monitoring web pages for updates, storing historical snapshots, and alerting users about changes. However, it has a vulnerability that allows attackers to exploit the backup restore feature, leading to arbitrary file reads from the local filesystem.
Vulnerability Detail
The vulnerability arises from the application's trust in attacker-controlled snapshot paths restored from backup files. When a backup ZIP is restored, the application extracts the archive and directly copies restored directories into the live datastore, preserving potentially malicious files like 'history.txt'. This file can contain paths to sensitive local files, which the application may read without proper validation. As a result, an attacker can craft a backup ZIP that, when restored, allows them to access arbitrary local files, including sensitive system files.
How To Fix
Latest published version: 0.60.9 as of 22 Oct 2026
pip install --upgrade "changedetection-io==0.60.9"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
0.55.1
This is the first release that contains the fix.
pip install --upgrade "changedetection-io==0.55.1"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If immediate patching is not possible, consider implementing a workaround by manually reviewing and sanitizing the contents of 'history.txt' before restoring backups. Ensure that no absolute or external paths are present in the file.
Conclusion
CVE-2026-43891 is a critical vulnerability in changedetection.io that allows attackers to read arbitrary local files through a crafted backup restore. It is essential to update to the patched version to secure your application and prevent unauthorized access to sensitive data.
See every vulnerability recorded for changedetection-io →
FAQ
CVE-2026-43891 is a vulnerability in changedetection.io that allows arbitrary local file reads through a crafted backup restore.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which monitors open-source vulnerabilities without requiring signup.
The vulnerability can lead to exposure of sensitive local files, including system configurations and application secrets, which can compromise the security of the application and the host system.
Yes, a patch is available in version 0.55.1 of the changedetection.io package. It is recommended to update to this version to mitigate the vulnerability.
If you cannot update immediately, review and sanitize the 'history.txt' file in backups to ensure it does not contain any untrusted paths before restoring.
References
Related vulnerabilities
Recent vulnerabilities recorded for changedetection-io.
