# CVE-2026-57898: Path traversal in Eclipse BaSyx - Java Server SDK

> Remote attackers can write arbitrary files via path traversal in the AAS thumbnail API when using the MongoDB backend, potentially leading to remote code execution.

- **Severity:** Critical 9.0 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jul 2026
- **Updated:** 31 Aug 2026
- **Also known as:** GHSA-4w7g-2ph6-pm6g

## What is CVE-2026-57898?

CVE-2026-57898 is a critical path traversal vulnerability in Eclipse BaSyx - Java Server SDK, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Eclipse BaSyx Java Server SDK versions 2.0.0-milestone-05 to 2.0.0-milestone-12, deployments using the MongoDB backend are vulnerable to an unauthenticated arbitrary file write through the AAS thumbnail API.

The AAS thumbnail upload path accepted a client-controlled fileName request parameter and passed it through repository file handling as both a repository key and, during thumbnail retrieval, a local filesystem path. With the MongoDB file repository, the supplied filename was treated as an opaque GridFS key and was not normalized or restricted as a filesystem path. A remote attacker could upload thumbnail content using an absolute or traversal-style filename, then trigger thumbnail retrieval so that the uploaded bytes were written to the attacker-chosen path on the server filesystem.

This could allow writing files anywhere the Java process has permission to write and may lead to remote code execution. The default InMemory backend is not affected by this specific path because it normalizes and restricts file paths to its temporary directory.

The issue is fixed in Eclipse BaSyx Java Server SDK 2.0.0-milestone-13.

Weakness: CWE-73 (External Control of File Name or Path), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-57898?


## How do I fix CVE-2026-57898?

No fix has been published for CVE-2026-57898 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57898 being exploited?

There is no known exploitation of CVE-2026-57898 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57898 and fix it if it is affected.

What it is: CVE-2026-57898 is a critical path traversal vulnerability in Eclipse BaSyx - Java Server SDK, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-57898 in the wild and no public exploit code.

Affected product: Eclipse BaSyx - Java Server SDK. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-57898/ (Markdown: https://insights.sbomify.com/CVE-2026-57898/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57898
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57898
- OSV: https://osv.dev/vulnerability/CVE-2026-57898

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57898/
Summaries are generated and may contain mistakes; the official description above is the record.