CVE-2026-53581

ntp: write path traversal

Published: Sep 8, 2026Updated: Sep 9, 2026 Sources: CVE List NVDCWE-22

9.0CRITICAL

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:HPrivileges Required

High

UI:NUser Interaction

None

Scope

S:CScope

Changed

Impact

C:HConfidentiality

High

I:LIntegrity

Low

A:HAvailability

High

Open in CVSS calculator →

Weaknesses

CWE-22 CWE-73

Affected Products

opnsense

oss-project

coreOn-prem

Networking Infrastructure / firewall

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Is your org exposed to CVE-2026-53581?Request an assessment to establish which checks are appropriate for your systems. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

2 techniques

Collection

Discovery

View detailed technique mapping

References

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

github.com

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-53581 and every CVE in our database. Create a free account — no credit card required.

Create Free Account

Plain-language analysis

Impact assessment and exploitation scenario in plain English

Attack graph visualization

Interactive attack path and kill chain mapping

Exploit details & PoC links

ExploitDB, Metasploit, GitHub PoCs with direct links

Nuclei scanner templates

Ready-to-use vulnerability scanner templates

Full remediation guide

Patch instructions, workarounds, and compliance impact

Interactive AI chat

Ask questions about this vulnerability in natural language

Related vulnerabilities

Semantically similar CVEs and attack patterns

REST API & MCP access

Integrate vulnerability data into your workflows