# CVE-2026-25228: SignalK Server has Path Traversal leading to information disclosure

> Authenticated attackers on Windows can read, write, and list arbitrary files via path traversal in the applicationData API.

- **Severity:** Medium 5.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Feb 2026
- **Updated:** 4 Feb 2026
- **Also known as:** GHSA-vrhw-v2hw-jffx

## What is CVE-2026-25228?

CVE-2026-25228 is a medium-severity path traversal vulnerability in signalk-server, published on 2 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Signal K Server is a server application that runs on a central hub in a boat. Prior to 2.20.3, a path traversal vulnerability in SignalK Server's applicationData API allows authenticated users on Windows systems to read, write, and list arbitrary files and directories on the filesystem. The validateAppId() function blocks forward slashes (/) but not backslashes (\), which are treated as directory separators by path.join() on Windows. This enables attackers to escape the intended applicationData directory. This vulnerability is fixed in 2.20.3.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-25228?

2 open source packages ship an affected version, including signalk-server. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `signalk-server` | npm | All versions | 2.20.3 |
| `signalk-server` | npm | All versions | 2.20.3 |

Products: Signalk Signal K Server.

## How do I fix CVE-2026-25228?

Upgrade signalk-server to 2.20.3 or later.

## Is CVE-2026-25228 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25228 exists.

## Other vulnerabilities in signalk-server

- [CVE-2026-23515](https://insights.sbomify.com/CVE-2026-23515/): RCE - Command Injection in Signal K set-system-time plugin (critical 10.0)
- [CVE-2025-66398](https://insights.sbomify.com/CVE-2025-66398/): Signal K Server has Unauthenticated State Pollution leading to Remote Code Execution (RCE) (critical 9.7)
- [CVE-2026-33950](https://insights.sbomify.com/CVE-2026-33950/): signalk-server: Privilege Escalation by Admin Role Injection via /enableSecurity (critical 9.4)
- [CVE-2025-68620](https://insights.sbomify.com/CVE-2025-68620/): Signal K Server vulnerable to JWT Token Theft via WebSocket Enumeration and Unauthenticated Polling (critical 9.1)
- [CVE-2026-41893](https://insights.sbomify.com/CVE-2026-41893/): Signal K Server's WebSocket Login Endpoint Lacks Rate Limiting (Credential Brute-Force) (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-25228 and fix it if it is affected.

What it is: CVE-2026-25228 is a medium-severity path traversal vulnerability in signalk-server, published on 2 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25228 exists.

Affected packages and fixed versions:
- signalk-server (npm): affected all versions; fixed in 2.20.3
- signalk-server (npm): affected all versions; fixed in 2.20.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-25228/ (Markdown: https://insights.sbomify.com/CVE-2026-25228/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25228
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25228
- OSV: https://osv.dev/vulnerability/CVE-2026-25228

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-25228/
Summaries are generated and may contain mistakes; the official description above is the record.