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Fencer Vulns
medium 5.4

CVE-2026-26952 json

Pi-hole Web Interface has Stored HTML Injection via Local DNS Records (CNAME/Hosts) in data-tag Attribute

published 2026-02-19 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-8428

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level ad and internet tracker blocking application. Versions 6.4 and below are vulnerable to stored HTML injection through the local DNS records configuration page, which allows an authenticated administrator to inject code that is stored in the Pi-hole configuration and rendered every time the DNS records table is viewed. The populateDataTable() function contains a data variable with the full DNS record value exactly as entered by the user and returned by the API. This value is inserted directly into the data-tag HTML attribute without any escaping or sanitization of special characters. When an attacker supplies a value containing double quotes ("), they can prematurely “close” the data-tag attribute and inject additional HTML attributes into the element. Since Pi-hole implements a Content Security Policy (CSP) that blocks inline JavaScript, the impact is limited. This issue has been fixed in version 6.4.1.

Patch / fix

  • pi-hole pi-hole 6.4.1
  • pi-hole web_interface 6.4.1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

  • pi-hole web

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-116 Improper Encoding or Escaping of Output

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.