XSS in Pi-Hole Web
CVE-2026-33406
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (29.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Pi-Hole Web — versions >= 6.0, < 6.5
- Pi-Hole Web Interface
Weakness classification (CWE)
References
- github.com/pi-hole/web/security/advisories/GHSA-9rfm-c5g6-538p (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-33406?
- CVE-2026-33406 is a medium-severity vulnerability in Pi-Hole Web, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-04-06.
- How severe is CVE-2026-33406?
- Medium severity. CVSS v3 base score is 5.4 out of 10.