dgtlmoon changedetection.io up to 0.54.0 URL Validation is_safe_valid_url server-side request forgery

Summaryinfo

A vulnerability has been found in dgtlmoon changedetection.io up to 0.54.0 and classified as critical. This vulnerability affects the function is_safe_valid_url of the component URL Validation Handler. The manipulation leads to server-side request forgery. This vulnerability is referenced as CVE-2026-27696. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, has been found in dgtlmoon changedetection.io up to 0.54.0. This issue affects the function is_safe_valid_url of the component URL Validation Handler. The manipulation with an unknown input leads to a server-side request forgery vulnerability. Using CWE to declare the problem leads to CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

changedetection.io is a free open source web page change detection tool. In versions prior to 0.54.1, changedetection.io is vulnerable to Server-Side Request Forgery (SSRF) because the URL validation function `is_safe_valid_url()` does not validate the resolved IP address of watch URLs against private, loopback, or link-local address ranges. An authenticated user (or any user when no password is configured, which is the default) can add a watch for internal network URLs. The application fetches these URLs server-side, stores the response content, and makes it viewable through the web UI — enabling full data exfiltration from internal services. Version 0.54.1 contains a fix for the issue.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-27696 since 02/23/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 0.54.1 eliminates this vulnerability. Applying the patch fe7aa38c651d73fe5f41ce09855fa8f97193747b is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-8622). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• dgtlmoon

Name

• changedetection.io

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38
• 0.39
• 0.40
• 0.41
• 0.42
• 0.43
• 0.44
• 0.45
• 0.46
• 0.47
• 0.48
• 0.49
• 0.50
• 0.51
• 0.52
• 0.53
• 0.54.0

License

• open-source

Website

• Product: https://github.com/dgtlmoon/changedetection.io/

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Be aware that VulDB is the high quality source for vulnerability data.

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