# CVE-2026-35085: MBS Universal Gateway stack buffer overflow in gdv-serverconfig

Source: https://junglewise.ai/threats/cve-2026-35085-mbs-universal-gateway-stack-buffer-overflow-in-gdv-serverconfig  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-03. Updated: 2026-06-03  
License: CC BY 4.0 with a link back

CVE-2026-35085 · Severity: high · CVSS 8.8 · Published 2026-06-03

MBS Universal Gateways, which connect different communication protocols in building automation systems, are vulnerable to a security flaw in their configuration interface. An attacker with basic user credentials can exploit this to take complete control of the device with administrative (root) privileges. This could lead to a total compromise of the building automation network, allowing unauthorized access to sensitive configuration data or disruption of building operations.

Technologies: [MBS GmbH Universal Gateway Firmware](https://junglewise.ai/threats/technologies/universal-gateway-firmware). Vendors: [MBS GmbH](https://junglewise.ai/threats/vendors/mbs-gmbh).

## Quick answers

**Is CVE-2026-35085 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-35085 being exploited in the wild.

**How severe is CVE-2026-35085?** High severity, with a CVSS score of 8.8, published 3 June 2026.

**Which products and versions are affected?** MBS GmbH Universal Gateway (UGW) Firmware < V6_0_0_7.

**Is there a fix for CVE-2026-35085?** A patch was published on 2026-06-03: Fixed in firmware V6_0_0_7 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-35085 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-35085?** Check whether you run MBS GmbH Universal Gateway Firmware. 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

A stack-based buffer overflow (CWE-121) exists in the gdv-serverconfig CGI endpoint of the MBS Universal Gateway (UGW) web GUI. The vulnerability is caused by insufficient bounds checking on user-supplied input. A remote attacker with authenticated user-level privileges can exploit this flaw via network requests to execute arbitrary code with root privileges. This leads to a full system compromise, including the ability to read/delete files and cause a denial of service. The issue is fixed in firmware version V6_0_0_7.

## Affected products

- MBS GmbH Universal Gateway (UGW) Firmware < V6_0_0_7

## Timeline

- 2026-06-03: disclosed
- 2026-06-03: advisory
- 2026-06-03: patched: Fixed in firmware V6_0_0_7

## References

- [https://www.certvde.com/en/advisories/VDE-2026-039/](https://www.certvde.com/en/advisories/VDE-2026-039/)

## Related threats

- [MBS Universal Gateway stack buffer overflow in dali-devconfig](https://junglewise.ai/threats/cve-2026-35084-mbs-universal-gateway-stack-buffer-overflow-in-dali-devconfig)
- [MBS Universal Gateway stack buffer overflow in web GUI](https://junglewise.ai/threats/cve-2026-35083-mbs-universal-gateway-stack-buffer-overflow-in-web-gui)
- [MBS Universal Gateway arbitrary file deletion in ugw-restoreinfo](https://junglewise.ai/threats/cve-2026-35080-mbs-universal-gateway-arbitrary-file-deletion-in-ugw-restoreinfo)
- [MBS Universal Gateway arbitrary file deletion in ugw-restore](https://junglewise.ai/threats/cve-2026-35079-mbs-universal-gateway-arbitrary-file-deletion-in-ugw-restore)
- [MBS Universal Gateway arbitrary file deletion in ugw-delete-file](https://junglewise.ai/threats/cve-2026-35077-mbs-universal-gateway-arbitrary-file-deletion-in-ugw-delete-file)