HTML Attribute Injection in Pi-hole Admin Interface for Pi-hole
CVE-2026-33406

5.4MEDIUM

Key Information:

Vendor

Pi-hole

Status
Web
Vendor
CVE Published:
6 April 2026

What is CVE-2026-33406?

The Pi-hole Admin Interface, which facilitates the management of the Pi-hole network-level ad and internet tracker blocking application, is susceptible to HTML attribute injection. This vulnerability arises from configuration values accessed via the /api/config endpoint that are directly inserted into HTML value attributes without proper escaping in settings-advanced.js. Malicious actors can exploit this by introducing a double quote into any config value, causing a break from the attribute context. Though the server's Content Security Policy restricts JavaScript execution, the injected attributes can still modify element styling, leading to UI redressing. The primary attack vector includes importing a compromised teleporter backup that circumvents standard server-side validation for individual fields. The vulnerability is addressed in version 6.5.

Affected Version(s)

web >= 6.0, < 6.5

References

https://github.com/pi-hole/web/security/advisories/GHSA-9...
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CVSS V3.1

Score:
5.4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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