ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-39849

Pi-hole FTL is the core engine of the Pi-hole network-level advertisement and tracker blocker.

Published May 5, 2026 · catalog updated Jul 24, 2026 · Pi-hole FTL is the

Check if you run it

No confirmed exploitation is on record for CVE-2026-39849. EPSS is 1.00%. Act only if a listed version of Pi-hole FTL is the is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Pi-hole FTL is the).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High8.7
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
1.00%
Remediation
Advisory link
Affected products
cpe pi-hole/ftldns

Pi-hole FTL is the core engine of the Pi-hole network-level advertisement and tracker blocker. In versions before 6.6.1, the configuration field in Pi-hole FTL accepted newline characters without validation, allowing an attacker to inject arbitrary directives into the generated dnsmasq configuration file. On installations with no admin password set (the default for many deployments), the configuration API is fully accessible without credentials, allowing a network-adjacent attacker to inject the payload, enable the built-in DHCP server, and achieve arbitrary command execution on the host the next time any device on the network requests a DHCP lease. The injected value is persisted to /etc/pihole/pihole.toml and survives restarts. The strncpy in the code path limits the total interface field to 31 bytes, but payloads such as wlan0\ndhcp-script=/tmp/p fit within this constraint. The dnsmasq config validation introduced in FTL 6.6 only checks syntactic validity, so valid directives injected via newline pass validation successfully. This issue has been fixed in version 6.6.1.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe pi-hole/ftldns6.6

How to fix CVE-2026-39849

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-39849. EPSS is 1.00%. Act only if a listed version of Pi-hole FTL is the is installed.

Which versions are affected?

Compare what you have installed with 6.6. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-93. EPSS 1.00%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 5, 2026 · NIST NVD

    Detected

    Pi-hole FTL is the core engine of the Pi-hole network-level advertisement and tracker blocker. In versions before 6.6.1, the configuration field in Pi-hole FTL accepted newline characters without validation, allowing an attacker to inject arbitrary directives into the generated dnsmasq configuration file. On installations with no admin password set (the default for many deployments), the configura

  2. Jul 24, 2026 · NIST NVD

    Updated

    Pi-hole FTL is the core engine of the Pi-hole network-level advertisement and tracker blocker. In versions before 6.6.1, the configuration field in Pi-hole FTL accepted newline characters without validation, allowing an attacker to inject arbitrary directives into the generated dnsmasq configuration file. On installations with no admin password set (the default for many deployments), the configura

Sources

  • CVE.orgVulnerability recordCVE-2026-39849

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-39849

    30-day exploitation probability 1.0%

    first.org
  • NIST NVDVulnerability recordCVE-2026-39849

    Pi-hole FTL is the core engine of the Pi-hole network-level advertisement and tracker blocker. In versions before 6.6.1, the configuration field in Pi-hole FTL accepted newline characters without validation, allowing an attacker to inject arbitrary directives into

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.