CVE-2026-35521: pi-hole ftl OS Command Injection

Vulnerability summary

CVE-2026-35521 is a high (CVSS 8.8) OS Command Injection vulnerability in pi-hole ftl. EPSS estimates a 1.04% chance of exploitation in the next 30 days, higher than 63.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 07-04-2026
   PublishedVulnerability first disclosed.
2. 07-04-2026
   Last modifiedVulnerability information updated.

Description

FTLDNS (pihole-FTL) provides an interactive API and also generates statistics for Pi-hole's Web interface. From 6.0 to before 6.6, the Pi-hole FTL engine contains a Remote Code Execution (RCE) vulnerability in the DHCP hosts configuration parameter (dhcp.hosts). This vulnerability allows an authenticated attacker to inject arbitrary dnsmasq configuration directives through newline characters, ultimately achieving command execution on the underlying system. This vulnerability is fixed in 6.6.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
• CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.