Authenticated command execution via DHCP newline injection
Published Apr 7, 2026 · Updated Apr 7, 2026
Command injection in Pi-hole FTL 6.0 through 6.5 allows remote authenticated users to execute arbitrary commands through its API. FTL's dhcp.leaseTime handler accepts newlines because validate_stub always returns true, then fprintf writes the value into dnsmasq.conf. Administrative API access and a DNS-service restart are required; injected leasefile-ro and dhcp-script directives invoke a shell on the Linux host.
Summary
What happened
Command injection in Pi-hole FTL 6.0 through 6.5 allows remote authenticated users to execute arbitrary commands through its API. FTL's dhcp.leaseTime handler accepts newlines because validate_stub always returns true, then fprintf writes the value into dnsmasq.conf. Administrative API access and a DNS-service restart are required; injected leasefile-ro and dhcp-script directives invoke a shell on the Linux host.
The record
- CVE
- CVE-2026-35520
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Vendor
- Pi-hole
- Product
- Pi-hole FTL
- Classifications
- CWE-20, CWE-93, CWE-78, T1059.004, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 7, 2026CVE publishedPublication date reported by the CVE source.
- Apr 7, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 6.0, < 6.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-fqv2-qhfh-ghcj proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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