CVE-2026-54429 Details

A denial-of-service vulnerability has been identified in Siemens SIMATIC S7-PLCSIM Advanced, affecting all versions. The issue arises because the application does not properly manage high-volume multicast network traffic, leading to memory exhaustion. This flaw can be exploited by an unauthenticated attacker on the local network segment, causing the application to become inaccessible and requiring a manual restart, although no project data is lost. Successful exploitation depends on having a specific project configuration active on the targeted instance.

Currently, no fix is available. However, Siemens recommends restricting multicast traffic on the network segment where SIMATIC S7-PLCSIM Advanced is running. Users can also disable the S7-PLCSIM Virtual Switch binding on the network adapter used by the affected instance, which removes the attack vector entirely. Alternatively, 'Softbus' or 'PLCSIM' network modes can be used, as these do not accept any packets from the network. For general security, Siemens advises protecting network access to devices and following operational guidelines for Industrial Security.