VulnerabilityDeferred

CVE-2026-41489

From 6.0 to before Core 6.4.2 and FTL 6.6.1, two shell scripts executed as root by systemd (pihole-FTL-prestart.sh and pihole-FTL-poststop.sh) read the files.pid path from this config without validation and use it in privileged file operations (install…

HIGH 8.8EPSS 0.13%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Pi-hole is a DNS sinkhole that protects devices from unwanted content without installing any client-side software. From 6.0 to before Core 6.4.2 and FTL 6.6.1, two shell scripts executed as root by systemd (pihole-FTL-prestart.sh and pihole-FTL-poststop.sh) read the files.pid path from this config without validation and use it in privileged file operations (install and rm -f). By writing an arbitrary path into files.pid, an attacker with pihole privilege can cause root to delete and then recreate any file on the system outside the ProtectSystem=full-restricted directories, gaining write access to it. On a default Pi-hole installation this yields local privilege escalation to root via SSH authorized keys manipulation. If /root/.ssh/authorized_keys does not exist (default on fresh installs), only ExecStartPre is required. If the file exists, ExecStopPost deletes it first, and the same restart triggers both hooks in sequence. This vulnerability is fixed in Core 6.4.2 and FTL 6.6.1.

CVSS 3.1: 8.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS: 0.13% probability · 3th percentile
CISA KEV: Not listed
Weakness: CWE-15, CWE-269, CWE-732
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.