CVE-2025-40556

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-13 · updated 2026-06-17
Weakness: CWE-20

Description

A vulnerability has been identified in BACnet ATEC 550-440 (All versions), BACnet ATEC 550-441 (All versions), BACnet ATEC 550-445 (All versions), BACnet ATEC 550-446 (All versions). Affected devices improperly handle specific incoming BACnet MSTP messages. This could allow an attacker residing in the same BACnet network to send a specially crafted MSTP message that results in a denial of service condition of the targeted device. A power cycle is required to restore the device's normal operation.

Affected products

Siemens BACnet ATEC 550-440: all versions
Siemens BACnet ATEC 550-441: all versions
Siemens BACnet ATEC 550-445: all versions
Siemens BACnet ATEC 550-446: all versions

References

https://cert-portal.siemens.com/productcert/html/ssa-828116.html

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