A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions <

Summary

A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions < V5.2), Nucleus ReadyStart V3 (All versions < V2012.12), Nucleus Source Code (All versions), PLUSCONTROL 1st Gen (All versions), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). Initial Sequence Numbers (ISNs) for TCP connections are derived from an insufficiently random source. As a result, the ISN of current and future TCP connections could be predictable. An attacker could hijack existing sessions or spoof future ones.

Timeline

1. Feb 9, 2021, 12:00 AM UTCCVE published
2. Jun 2, 2026, 7:29 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Jun 2, 2026, 8:14 PM UTCRecord last updated

Affected versions

• Siemens APOGEE PXC Compact (BACnet)

  All versions < V3.5.5

• Siemens APOGEE PXC Compact (P2 Ethernet)

  All versions < V2.8.20

• Siemens APOGEE PXC Modular (BACnet)

  All versions < V3.5.5

• Siemens APOGEE PXC Modular (P2 Ethernet)

  All versions < V2.8.20

• Siemens Nucleus NET

  All versions < V5.2

• Siemens Nucleus ReadyStart V3

  All versions < V2012.12

• Siemens Nucleus Source Code

  All versions

• Siemens PLUSCONTROL 1st Gen

  All versions

• Siemens TALON TC Compact (BACnet)

  All versions < V3.5.5

• Siemens TALON TC Modular (BACnet)

  All versions < V3.5.5

References 4