CVE-2026-33406

In the Pi-hole Admin Interface, the formatInfo() function in queries.js renders data.upstream, data.client.ip, and data.ede.text into HTML without escaping when a user expands a query row in the Query Log, enabling stored HTML injection. JavaScript execution is blocked by the server's CSP (script-src 'self'). The vulnerability is fixed in 6.5.

In the Pi-hole Admin Interface, client hostnames and IP addresses from the FTL database are rendered into the DOM without escaping in network.js and charts.js/index.js. Although upstream validation in dnsmasq and FTL blocks HTML characters via normal DHCP/DNS paths, the web UI performs no output escaping, inconsistent with other fields. The vulnerability is fixed in 6.5.

Pi-hole Admin Interface versions 6.0 to before 6.5 contain a reflected DOM-based XSS vulnerability in taillog.js. An unauthenticated attacker can inject arbitrary HTML into the admin interface via a crafted URL because the file parameter is interpolated into innerHTML without escaping. The missing form-action directive in Content-Security-Policy allows injected forms to exfiltrate credentials. The vulnerability is fixed in 6.5.

Pi-hole Admin Interface before version 6.3 is vulnerable to CRLF injection. When a request is made to a file ending with the .lp extension, the application performs a redirect without proper input sanitization. An attacker can inject carriage return and line feed characters (%0d%0a) to manipulate both headers and content of the HTTP response, enabling injection of arbitrary HTTP response headers, potentially leading to session fixation, cache poisoning, and weakening or bypassing browser-based security mechanisms such as CSP or X-XSS-Protection.

Pi-hole Admin Interface versions 6.2.1 and earlier are vulnerable to reflected cross-site scripting (XSS) via a malformed URL path. The 404 error page includes the requested path in the class attribute of the body tag without proper sanitization or escaping.

Pi-hole Admin Interface versions prior to 6.3 are vulnerable to cross-site scripting (XSS) via the Address field in the Subscribed Lists group management section. An authenticated user can inject malicious JavaScript that executes when another user navigates to the Tools section and performs a gravity database update. The vulnerability is patched in version 6.3.