# CVE-2026-55552: Yamcs unauthenticated directory traversal

Source: https://junglewise.ai/threats/cve-2026-55552-yamcs-unauthenticated-directory-traversal  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-28. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-55552 · Severity: high · CVSS 7.5 · Published 2026-08-28

Yamcs is an open-source mission control system used to manage and monitor satellite operations and other space-related infrastructure. This vulnerability allows anyone on the network to download any file from the server's operating system—including configuration files, credentials, and system files—without needing to log in. An attacker could retrieve sensitive data that could lead to further compromise of the system or exposure of operational secrets.

Technologies: [org.yamcs:yamcs-core (Maven)](https://junglewise.ai/threats/technologies/org-yamcs-yamcs-core). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2026-55552 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-55552 being exploited in the wild.

**How severe is CVE-2026-55552?** High severity, with a CVSS score of 7.5, published 28 August 2026.

**Which products and versions are affected?** org.yamcs:yamcs-core (Maven) < 5.11.13, ECOSYSTEM:introduced=0,fixed=5.12.0.

**Is there a fix for CVE-2026-55552?** Yes. org.yamcs:yamcs-core (Maven): upgrade to 5.12.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-55552 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-55552?** Check whether you run org.yamcs:yamcs-core (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.yamcs:yamcs-core (Maven): upgrade to 5.12.0 or later

  ```sh
  # set org.yamcs:yamcs-core to 5.12.0 in your pom.xml or build.gradle
  ```


## Technical details

This is a path traversal (CWE-22) vulnerability affecting the static file serving functionality in HttpRequestHandler.java and StaticFileHandler.java. The vulnerability allows unauthenticated attackers to bypass directory restrictions by injecting path traversal sequences (e.g., `//etc/passwd`) into HTTP requests. No authentication or user interaction is required; the flaw is exploitable directly over the network via HTTP. An attacker can download any file readable by the Yamcs process user, including system configuration, application secrets, and potentially private keys. The vulnerability was patched in versions 5.11.13 and 5.12.0.

## Affected products

- Yamcs Yamcs <5.11.13

## Identifiers

- CVE-2026-55552
- GHSA-9jg3-g3wh-w9pj

## Timeline

- 2026-07-14: disclosed: Initial disclosure to GitHub Advisory Database
- 2026-08-28: advisory: Published to GitHub Advisory Database

## References

- [https://api.github.com/users/suffs811](https://api.github.com/users/suffs811)
- [https://github.com/suffs811](https://github.com/suffs811)
- [https://api.github.com/users/suffs811/gists%7B/gist_id%7D](https://api.github.com/users/suffs811/gists%7B/gist_id%7D)
- [https://api.github.com/users/suffs811/repos](https://api.github.com/users/suffs811/repos)
- [https://avatars.githubusercontent.com/u/84633135?v=4](https://avatars.githubusercontent.com/u/84633135?v=4)
- [https://api.github.com/users/suffs811/events%7B/privacy%7D](https://api.github.com/users/suffs811/events%7B/privacy%7D)

## Related threats

- [Yamcs DOM XSS in Extension Routing](https://junglewise.ai/threats/cve-2026-55566-yamcs-dom-xss-in-extension-routing)
- [Yamcs remote code execution via unescaped StreamSQL LIKE pattern](https://junglewise.ai/threats/cve-2026-55565-yamcs-remote-code-execution-via-unescaped-streamsql-like-pattern)
- [Yamcs remote code execution via YAML injection in instance template](https://junglewise.ai/threats/cve-2026-55559-yamcs-remote-code-execution-via-yaml-injection-in-instance)
- [Yamcs reflected XSS in authorize endpoint](https://junglewise.ai/threats/cve-2026-55549-yamcs-reflected-xss-in-authorize-endpoint)
- [Yamcs missing authorization on role and privilege enumeration endpoints](https://junglewise.ai/threats/cve-2026-55547-yamcs-missing-authorization-on-role-and-privilege-enumeration)