Strix
26.1K

CVE-2026-26953

MEDIUMCVSS 5.4/10EPSS 0.29%

Last modified

CVE-2026-26953 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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. EPSS estimates a 0.29% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS Probability
0.29%

21.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
Pi-HoleWeb Interface>= 6.0, < 6.4.1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-26953?
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.
How severe is CVE-2026-26953?
CVE-2026-26953 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.
How do I fix CVE-2026-26953?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-26953?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST