Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-35520 is a high-severity OS Command Injection (CWE-78) vulnerability. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 50th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-35520 is a remote code execution (RCE) vulnerability in the Pi-hole FTL engine, also known as FTLDNS, which provides an interactive API and generates statistics for Pi-hole's web interface. Affecting versions from 6.0 up to but not including 6.6, the flaw resides in the DHCP lease time configuration parameter (dhcp.leaseTime). It enables an authenticated attacker to inject arbitrary dnsmasq configuration directives by exploiting newline characters, resulting in command execution on the underlying system. The vulnerability is associated with CWE-78 (OS Command Injection) and CWE-93 (Improper Neutralization of CRLF Sequences), and carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
An authenticated attacker with low privileges can exploit this vulnerability remotely over the network with low complexity and no user interaction required. By manipulating the dhcp.leaseTime parameter through the FTL API, the attacker injects malicious dnsmasq directives separated by newlines, which the engine processes and executes as system commands. Successful exploitation grants high confidentiality, integrity, and availability impacts, potentially allowing full compromise of the host system running Pi-hole.
The official advisory on GitHub (GHSA-fqv2-qhfh-ghcj) confirms the vulnerability is fixed in Pi-hole FTL version 6.6, recommending immediate upgrades for affected installations. No additional mitigations are detailed beyond patching, emphasizing the need for authentication controls on the FTL API in the interim.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19713
Vulnerability Data
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 lease time configuration parameter (dhcp.leaseTime). This vulnerability…
more
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(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
—
V1.2.5V1.2.8V15.2.5V4.2.4
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect command sanitization during development.
Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.
Least privilege reduces the permissions available to any process that could be subverted by injected commands.
Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.
Secure engineering principles require proper neutralization of untrusted input before command construction.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.
Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.
Secure development lifecycle mandates input validation and output encoding that directly prevents CRLF injection.
Application security requirements include rules for neutralizing special characters such as CRLF in inputs.
Secure architecture principles encourage safe handling of untrusted data but do not prescribe specific CRLF controls.
Secure coding standards explicitly require neutralization of CRLF sequences, fully addressing this weakness.