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Medium · 5.4 CVE-2026-33406 EUVD-2026-19285

Pi-hole has a Stored HTML attribute injection

Published Apr 6, 2026 · Updated Apr 7, 2026 · Assigned by GitHub_M

Description

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

VendorProductAffectedFixed
pi-hole web >= 6.0, < 6.5 —

References