CVE-2026-53581: Path Traversal (CVSS 9)

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.

Is your site exposed to CVE-2026-53581?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.0

CRITICAL

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

EPSS — Exploit Prediction

0.0033

Probability of exploitation

0.26%

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-22 Path Traversal

CWE-73 CWE-73

References

Other References

https://github.com/opnsense/core/security/advisories/GHSA-872g-g543-j37m https://github.com/opnsense/core/security/advisories/GHSA-872g-g543-j37m

Frequently Asked Questions

What is CVE-2026-53581? +

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. It has a CVSS v3.1 base score of 9.0 (CRITICAL).

How severe is CVE-2026-53581? +

CVE-2026-53581 has a CVSS v3.1 score of 9.0 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0033, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-53581? +

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.

Related Vulnerabilities

CVE-2026-65886

Joomla Extension - balbooa.com - Unauthenticated arbitrary file read in Gridbox < 2.20.2 - The photo viewer allows unauthenticated attackers …

CVE-2024-56514

Karmada is a Kubernetes management system that allows users to run cloud-native applications across multiple Kubernetes clusters and clouds. Prior …

CVE-2026-43965

Path traversal vulnerability in Gleam's dependency management allows arbitrary directory deletion via malicious build/packages/packages.toml content. Package keys read from build/packages/packages.toml …

CVE-2026-40605

Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to version 2.17.1, a path traversal …

CVE-2026-41140

Poetry is a dependency manager for Python. Prior to 2.3.4, the extractall() function in src/poetry/utils/helpers.py:410-426 extracts sdist tarballs without path …

CVE-2026-7766

Kenik Camera management Panel is vulnerable to Path Traversal vulnerability. An unauthenticated attacker can send GET request with arbitrary file …

CVE-2026-53581