External risk intelligence

Signal K Server Admin Role Injection Vulnerability.

CVE advisorySeverity: CRITICAL (CVSS 9.4)

CVE-2026-33950

Signal K Server is designed as a marine vessel hub application. While it is a network-accessible service, these servers are typically deployed within isolated local boat networks or private vessel area networks rather than being directly exposed to the public internet by design.

Privilege Escalation

Signalk Signal K Server

before 2.24.02.24.0

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in the Signal K Server application, which manages central hub functions on boats. This issue allows unauthenticated attackers to gain full administrator privileges, potentially enabling them to alter sensitive vessel data, reconfigure the server, or access restricted information. The vendor has released a patched version to address this vulnerability.

Unauthenticated access to vessel data and server controls.
Critical flaw could compromise sensitive operational data.
Confirm exposure and relevance for vessel operations.

Attack Path

How an attacker could exploit the issue

An attacker can exploit this vulnerability by sending a request to the Signal K Server's `/enableSecurity` endpoint. This allows them to bypass authentication and gain administrator privileges, which can then be used to alter vessel data or server settings.

No authentication is required.
Triggered via the `/enableSecurity` endpoint.
Full administrator access to the server.

Live Threat

Current exploitation, exposure, and threat context

An unauthenticated attacker could gain full administrator access to the Signal K server when supported by the advisory. This could allow them to modify sensitive vessel routing data and alter server configurations.

Vessel routing data and server configurations.
Network access to modify server settings.
Compromised vessel operations and data integrity.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability impacts Signal K Server deployments, which are typically managed by application or platform teams responsible for onboard vessel systems. The first actionable step is to identify all instances of the Signal K Server, determine their network exposure and criticality to vessel operations, and confirm the responsible owner. Remediation planning should then proceed based on this risk assessment, potentially involving coordination with marine electronics vendors.

Identify onboard Signal K Server deployments.
Verify network exposure and operational criticality.
Plan and execute vendor-coordinated updates.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is Signal K Server?

Signal K Server is a software application designed to act as a central data hub on marine vessels. It collects, processes, and distributes various types of nautical information, such as vessel routing data and sensor readings, allowing different onboard marine electronics to communicate effectively and provide a unified view of the boat's operations.

How does CVE-2026-33950 enable privilege escalation?

This vulnerability is classified as an improper authorization or authentication bypass weakness. Essentially, the server fails to verify the identity of someone trying to access its security settings. By interacting with a specific endpoint, an attacker can trick the system into granting them full administrator privileges without providing any valid credentials, effectively bypassing the server's access controls.

Can any network request trigger this bug?

The vulnerability is specifically triggered by accessing the `/enableSecurity` endpoint on the server. If this endpoint is not reached or if the server is running a patched version, this specific path to gaining administrative control is closed. Simply having network access to the server is the primary prerequisite for an attacker to attempt this interaction.

Why should I care if my boat uses Signal K Server?

According to Halo Surface Signal, while these servers are usually kept on private or isolated local vessel networks, they remain network-accessible services. If your boat's network is connected to the internet or an untrusted local Wi-Fi, the risk increases because an attacker could potentially reach the server remotely to modify critical navigation data or server configurations.

What is the first step to secure my server?

The most important immediate step is to audit your vessel systems to locate all active Signal K Server instances. Once identified, verify their network configuration to understand their accessibility. Finally, prioritize updating the software to version 2.24.0-beta.4 or newer, as this release includes the necessary security patch to fix the unauthorized admin access issue.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.