Summary
A vulnerability in Desigo DXR and PXC controllers has been identified that could allow an attacker to cause denial of service conditions by sending malformed BACnet packets. Recovery requires a device reset or reboot to restore normal functionality. Siemens has released new versions for the affected products and recommends to update to the latest versions.
The following versions of Siemens Desigo DXR and PXC Controllers are affected:
- Desigo DXR2 vers:intdot/<01.21.233.16-7862 (CVE-2026-59693)
- Desigo PXC3 vers:intdot/<01.21.233.16-7862 (CVE-2026-59693)
- Desigo PXC4 vers:intdot/<02.21.194.36-2715 (CVE-2026-59693)
- Desigo PXC5.E003 vers:intdot/<02.21.194.36-2715 (CVE-2026-59693)
- Desigo PXC5.E24 vers:intdot/<02.21.194.36-2715 (CVE-2026-59693)
- Desigo PXC7 vers:intdot/<02.21.194.36-2715 (CVE-2026-59693)
| CVSS | Vendor | Equipment | Vulnerabilities |
|---|---|---|---|
| v3 4.3 | Siemens | Siemens Desigo DXR and PXC Controllers | Improper Check for Unusual or Exceptional Conditions |
Background
- Critical Infrastructure Sectors: Commercial Facilities, Critical Manufacturing, Energy, Healthcare and Public Health, Transportation Systems
- Countries/Areas Deployed: Worldwide
- Company Headquarters Location: Germany
Vulnerabilities
CVE-2026-59693
The affected devices are vulnerable to a denial-of-service (DoS) vulnerability. An attacker can exploit this issue by sending a malformed BACnet packet, causing the device to stop responding to BACnet queries. Recovery requires a device reset or reboot to restore normal functionality.
Affected Products
Siemens Desigo DXR and PXC Controllers
Siemens
Desigo DXR2 < V01.21.233.16-7862, Desigo PXC3 < V01.21.233.16-7862, Desigo PXC4 < V02.21.194.36-2715, Desigo PXC5.E003 < V02.21.194.36-2715, Desigo PXC5.E24 < V02.21.194.36-2715, Desigo PXC7 < V02.21.194.36-2715
known_affected
Remediations
Vendor fix
Update to V01.21.233.16-7862 or later version Please contact your local Siemens office for additional support in obtaining the update.
Vendor fix
Update to V02.21.194.36-2715 or later version Please contact your local Siemens office for additional support in obtaining the update.
Relevant CWE: CWE-754 Improper Check for Unusual or Exceptional Conditions
Metrics
| CVSS Version | Base Score | Base Severity | Vector String |
|---|---|---|---|
| 3.1 | 4.3 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
Acknowledgments
- Thomas EBI of Sauter reported this vulnerability to Siemens
General Recommendations
As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security and following the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity
Additional Resources
For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories
Terms of Use
The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use
Legal Notice and Terms of Use
This product is provided subject to this Notification (https://www.cisa.gov/notification and this Privacy & Use policy (https://www.cisa.gov/privacy-policy
Recommended Practices
CISA recommends users take defensive measures to minimize the exploitation risk of these vulnerabilities. Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolate them from business networks. When remote access is required, use more secure methods, such as virtual private networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent version available. Also recognize VPN is only as secure as its connected devices.
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
Advisory Conversion Disclaimer
This ICSA is a verbatim republication of Siemens SSA-781903 from a direct conversion of the vendor's Common Security Advisory Framework (CSAF) advisory. This is republished to CISA's website as a means of increasing visibility and is provided "as-is" for informational purposes only. CISA is not responsible for the editorial or technical accuracy of republished advisories and provides no warranties of any kind regarding any information contained within this advisory. Further, CISA does not endorse any commercial product or service. Please contact Siemens ProductCERT directly for any questions regarding this advisory.
Revision History
- Initial Release Date: 2026-08-11
| Date | Revision | Summary |
|---|---|---|
| 2026-08-11 | 1 | Publication Date |
| 2026-08-13 | 2 | Initial CISA Republication of Siemens SSA-781903 advisory |
Legal Notice and Terms of Use
This product is provided subject to this Notification and this Privacy & Use policy.
Vendor
- Siemens