CVE-2026-41489

HIGH
Published May 11, 2026 Modified May 13, 2026 CWE-15 CWE-269 CWE-732

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.

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CVSS v3.1 Score

8.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0001
Probability of exploitation
0.02%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-15 CWE-15
CWE-269 CWE-269
CWE-732 CWE-732

References

Frequently Asked Questions

What is CVE-2026-41489? +
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. It has a CVSS v3.1 base score of 8.8 (HIGH).
How severe is CVE-2026-41489? +
CVE-2026-41489 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-41489? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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