# CVE-2026-75167: MBS X-Serie Gateway broken access control in user edit method

Source: https://junglewise.ai/threats/cve-2026-75167-mbs-x-serie-gateway-broken-access-control-in-user-edit-method  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-04. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-75167 · Severity: medium · CVSS 4.3 · Published 2026-09-04

The MBS X-Serie Gateway is a universal industrial gateway used in building automation and critical infrastructure to translate between different communication protocols (KNX, PROFIBUS, DALI, etc.). A vulnerability in the user management feature allows an authenticated attacker with a low-level "Standard" user account to reset passwords for any other user, potentially including administrative accounts, leading to unauthorized access and system compromise.

## Quick answers

**Is CVE-2026-75167 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-75167 being exploited in the wild.

**How severe is CVE-2026-75167?** Medium severity, with a CVSS score of 4.3, published 4 September 2026.

**Which products and versions are affected?** MBS X-Serie Gateway V6_00_05 and earlier.

**Is there a fix for CVE-2026-75167?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-75167 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-75167?** Check whether anything you run is named in the advisory. 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.

## Technical details

This is a broken access control vulnerability in the ugw-usr-edit method of the /cgi-bin/wwwugw.cgi CGI script. The flaw fails to properly validate that a Standard-role user can only modify their own account; instead, it allows changing the password of arbitrary accounts. The vulnerability is accessible to any authenticated user via HTTP/HTTPS on the built-in web server. An attacker with valid Standard credentials can exploit this to escalate privileges by taking over higher-privileged accounts (such as administrative accounts), gaining full control of the gateway device and its automation functions. Firmware version V6_00_05 and earlier are affected.

## Affected products

- MBS X-Serie Gateway V6_00_05 and earlier

## Timeline

- 2026-09-04: disclosed

## References

- [https://en.mbs-solutions.de/mbs](https://en.mbs-solutions.de/mbs)
- [https://en.mbs-solutions.de/xserie](https://en.mbs-solutions.de/xserie)