CVE-2026-26953 Pi-hole Web Interface has Stored HTML Injection via X-Forwarded-For Header in Active Sessions Table
Authenticated attackers can inject HTML into the active sessions table, potentially affecting administrators viewing the page.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-26953?
CVE-2026-26953 is a medium-severity cross-site scripting vulnerability in pi-hole web, published on 19 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-26953?
It affects 1 product.
Products include Pi-Hole Web Interface.
How do I fix CVE-2026-26953?
No fix has been published for CVE-2026-26953 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-26953 being exploited?
There is no known exploitation of CVE-2026-26953 in the wild and no public exploit code.
Other vulnerabilities in pi-hole web
- CVE-2026-33765 Pi-hole Web Interface has a Command Injection Vulnerability
- CVE-2023-23614 Improper session handling of "Remember me for 7 days" functionality
- CVE-2025-59151 Pi-hole Admin Interface vulnerable to HTTP response header injection via CRLF injection
- CVE-2021-3706 Sensitive Cookie Without 'HttpOnly' Flag in pi-hole/adminlte
- CVE-2021-41175 Stored XSS in Client Groups Management (Authenticated)
Sources
Also known as GHSA-8rw8-vjgp-rwj6.