ICSA-26-265-05: Siemens Desigo CC family

CISA's summary

Summary: A Client Code Execution (CCE) vulnerability has been identified in Desigo CC, potentially allowing malicious actors to execute arbitrary code on client devices through specially crafted graphics documents. This vulnerability leverages user-defined graphics containing embedded scripts that are executed on client application instances. Successful exploitation could lead to compromise of the client operating system and potential lateral movement within the organization.

Products, as the advisory lists them

DeSpy has not checked any unit, hardware revision or firmware.

Vulnerabilities in this advisory

• CVE-2026-34223 — CVE-2026-34223 · CWE-94

  The affected application is vulnerable to Client Code Execution (CCE) due to insufficient input validation when handling scripts embedded within user-defined graphics documents. Specifically, when the script within a graphics document is designed or modified by an attacker to include malicious commands. When a user opens a compromised graphics document, the embedded script is executed on the client application instance, allowing an attacker to write arbitrary files to the client's operating system. Successful exploitation requires an attacker to craft a malicious graphics document and entice a user with sufficient privileges to display it. This could lead to compromise of the client operating system and potential lateral movement within the organization.

Acknowledgments, as the advisory lists them

• Siemens ProductCERT: reported this vulnerability to CISA.

The advisory's legal notice

The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use.

Sources

• The advisory at cisa.gov
• The CSAF document (JSON)

DeSpy's copy of this version is dated 2026-09-28.