CVE-2026-33406: Pi-hole Web Interface

Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days.

Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level ad and internet tracker blocking application. From 6.0 to before 6.5, configuration values from the /api/config endpoint are placed directly into HTML value="" attributes without escaping in settings-advanced.js, enabling HTML attribute injection. A double quote in any config value breaks out of the attribute context. JavaScript execution is blocked by the server's CSP (script-src 'self'), but injected attributes can alter element styling for UI redressing. The primary attack vector is importing a malicious teleporter backup, which bypasses per-field server-side validation. This vulnerability is fixed in 6.5.

Affected products

• Pi-hole Web Interface: from 6.0, up to and including 6.4.1

Published 2026-04-06. Last modified 2026-06-17.