Description
OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.9 of opnsense/core and version 26.4_20 of BE/opnsense/core, a path traversal vulnerability in the NTP configuration module allows an attacker to overwrite arbitrary files on the system as the root user. By manipulating the GPS or PPS serial port parameter, an attacker with access to the NTP configuration can escape the intended directory and force the system to write user-controlled data to any file on the filesystem. Version 26.1.9 of opnsense/core and version 26.4_20 of BE/opnsense/core patch the issue.
Published: 2026-09-08
Score: 9 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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History

Wed, 09 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 08 Sep 2026 23:15:00 +0000

Type Values Removed Values Added
Description OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.9 of opnsense/core and version 26.4_20 of BE/opnsense/core, a path traversal vulnerability in the NTP configuration module allows an attacker to overwrite arbitrary files on the system as the root user. By manipulating the GPS or PPS serial port parameter, an attacker with access to the NTP configuration can escape the intended directory and force the system to write user-controlled data to any file on the filesystem. Version 26.1.9 of opnsense/core and version 26.4_20 of BE/opnsense/core patch the issue.
Title ntp: write path traversal
Weaknesses CWE-22
CWE-73
References
Metrics cvssV3_1

{'score': 9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:H'}


Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-09T13:37:23.831Z

Reserved: 2026-06-09T19:11:53.484Z

Link: CVE-2026-53581

cve-icon Vulnrichment

Updated: 2026-09-09T13:37:03.790Z

cve-icon NVD

Status : Received

Published: 2026-09-08T23:17:24.550

Modified: 2026-09-09T14:17:12.343

Link: CVE-2026-53581

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-09T08:45:07Z

Weaknesses