# 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.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Feb 2026
- **Updated:** 20 Feb 2026
- **Also known as:** GHSA-8rw8-vjgp-rwj6

## 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-20 (Improper Input Validation), CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2026-26953?

It affects 1 product.


Products: 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.

## 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](https://insights.sbomify.com/CVE-2026-33765/): Pi-hole Web Interface has a Command Injection Vulnerability (high 8.9)
- [CVE-2023-23614](https://insights.sbomify.com/CVE-2023-23614/): Improper session handling of "Remember me for 7 days" functionality (high 8.8)
- [CVE-2025-59151](https://insights.sbomify.com/CVE-2025-59151/): Pi-hole Admin Interface vulnerable to HTTP response header injection via CRLF injection (high 8.2)
- [CVE-2021-3706](https://insights.sbomify.com/CVE-2021-3706/): Sensitive Cookie Without 'HttpOnly' Flag in pi-hole/adminlte (high 7.4)
- [CVE-2021-41175](https://insights.sbomify.com/CVE-2021-41175/): Stored XSS in Client Groups Management (Authenticated) (high 7.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26953 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-26953 in the wild and no public exploit code.

Affected product: pi-hole web. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-26953/ (Markdown: https://insights.sbomify.com/CVE-2026-26953/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26953
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26953
- OSV: https://osv.dev/vulnerability/CVE-2026-26953

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26953/
Summaries are generated and may contain mistakes; the official description above is the record.