---
title: "CVE-2026-53581: OPNsense - Path Traversal"
description: "OPNsense < 26.1.9 (opnsense/core) and < 26.4_20 (BE/opnsense/core) contain a path traversal caused by manipulation of GPS or PPS serial port parameters in the NTP configuration module, letting attackers with NTP config access overwrite arbitrary files as root."
url: https://panop.io/threat-heartbeat/CVE-2026-53581/
---

# CVE-2026-53581 OPNsense - Path Traversal

OPNsense < 26.1.9 (opnsense/core) and < 26.4\_20 (BE/opnsense/core) contain a path traversal caused by manipulation of GPS or PPS serial port parameters in the NTP configuration module, letting attackers with NTP config access overwrite arbitrary files as root.

CVSS base score 9.0 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.47% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-53581)

## Details

Type

Path Traversal

Impact

File System Write

CVSS vector

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

Published

8 September 2026

Updated

15 October 2026

Weakness

[CWE-22](https://cwe.mitre.org/data/definitions/22.html)

## Vendor fix

Update to opnsense/core version 26.1.9 and BE/opnsense/core version 26.4\_20 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-53581](https://nvd.nist.gov/vuln/detail/CVE-2026-53581)
- [https://github.com/opnsense/core/security/advisories/GHSA-872g-g543-j37m](https://github.com/opnsense/core/security/advisories/GHSA-872g-g543-j37m)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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