Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-57898 – Unauthenticated Arbitrary File Write Leading to RCE – Eclipse BaSyx Java Server …

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-57898 is a critical unauthenticated arbitrary file write vulnerability (CWE-22 / CWE-73) in the Eclipse BaSyx Java Server SDK, affecting deployments that use the MongoDB backend across versions 2.0.0-milestone-05 through 2.0.0-milestone-12. By supplying a crafted fileName parameter to the AAS thumbnail API, a remote unauthenticated attacker can write arbitrary file content to any location the Java process has permission to access — a condition that may lead to remote code execution. The vulnerability carries a CVSS v3.1 base score of 9.0 (Critical).

Technical details

  • Root cause: The AAS thumbnail upload endpoint accepted a client-controlled fileName request parameter and passed it directly through file repository handling as both a GridFS key and a local filesystem path. With the MongoDB backend, the supplied filename was stored as an opaque GridFS key and was never normalized or restricted to a safe base directory.
  • Trigger conditions: An attacker sends a thumbnail upload request with an absolute path or path traversal sequence (e.g., ../../) as the fileName value. A subsequent thumbnail retrieval request causes the server to write the previously uploaded bytes to the attacker-controlled filesystem path.
  • Attack vector: Fully remote and unauthenticated — no credentials, session tokens, or user interaction are required. The attack is conducted entirely over the network via the HTTP REST API exposed by the server.
  • Impact: An attacker can write arbitrary files to any location the Java process can reach on the underlying host. The Eclipse Foundation’s own advisory explicitly states this condition "may lead to remote code execution." The vulnerability carries a Scope:Changed rating (S:C), reflecting the potential for impact beyond the vulnerable component itself. Confidentiality, integrity, and availability are all rated High.
  • Unaffected configuration: The default InMemory backend is not affected, because it normalizes and restricts file paths to its own temporary directory.

Affected software

  • Eclipse BaSyx Java Server SDK versions 2.0.0-milestone-05 through 2.0.0-milestone-12, when deployed with the MongoDB backend.
  • The default InMemory backend configuration is not affected.

Severity

  • CVSS v3.1 Base Score: 9.0 (Critical)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Mitigation and recommended actions

  • Patch immediately: Upgrade to Eclipse BaSyx Java Server SDK 2.0.0-milestone-13, which secures repository file paths and stream downloads to prevent path traversal exploitation. The fix was introduced in pull request #1024 and is available in the milestone-13 release on GitHub.
  • If immediate patching is not possible:
    • Avoid deploying the MongoDB backend in internet-exposed configurations until the patch is applied. Switching to the default InMemory backend eliminates this specific attack path.
    • Enforce strict network-layer access controls to restrict who can send requests to the AAS thumbnail API endpoints. Only trusted internal hosts should be permitted to reach these endpoints.
    • Monitor for unexpected file creation activity in directories accessible to the Java server process.

IONIX Status

The IONIX research team is tracking ongoing exploitation attempts and recommends immediate patching. Potentially affected assets are outlined in this post.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge