pi-hole web up to 6.4.0 cross site scripting

Summaryinfo

A vulnerability labeled as problematic has been found in pi-hole web up to 6.4.0. This vulnerability affects unknown code. Such manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2026-26953. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in pi-hole web up to 6.4.0. Affected by this issue is an unknown part. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-80. The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages. Impacted is integrity. CVE summarizes:

Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level ad and internet tracker blocking application. Versions 6.0 and above have a Stored HTML Injection vulnerability in the active sessions table located on the API settings page, allowing an attacker with valid credentials to inject arbitrary HTML code that will be rendered in the browser of any administrator who visits the active sessions page. The rowCallback function contains the value data.x_forwarded_for, which is directly concatenated into an HTML string and inserted into the DOM using jQuery’s .html() method. This method interprets the content as HTML, which means that any HTML tags present in the value will be parsed and rendered by the browser. An attacker can use common tools such as curl, wget, Python requests, Burp Suite, or even JavaScript fetch() to send an authentication request with an X-Forwarded-For header that contains malicious HTML code instead of a legitimate IP address. Since Pi-hole implements a Content Security Policy (CSP) that blocks inline JavaScript, the impact is limited to pure HTML injection without the ability to execute scripts. This issue has been fixed in version 6.4.1.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-26953 since 02/16/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

Upgrading to version 6.4.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 1a0c6f4fe6d0116fd2846b2adaae95996b7f194d 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.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• pi-hole

Name

• web

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4.0

License

• open-source

Website

• Product: https://github.com/pi-hole/web/

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