CVE-2025-40743: Siemens Sinumerik 828d ppu.4

High severity, CVSS 8.3. EPSS: 0.2% chance of exploitation in the next 30 days.

A vulnerability has been identified in SINUMERIK 828D PPU.4 (All versions < V4.95 SP5), SINUMERIK 828D PPU.5 (All versions < V5.25 SP1), SINUMERIK 840D sl (All versions < V4.95 SP5), SINUMERIK MC (All versions < V1.25 SP1), SINUMERIK MC V1.15 (All versions < V1.15 SP5), SINUMERIK ONE (All versions < V6.25 SP1), SINUMERIK ONE V6.15 (All versions < V6.15 SP5). The affected application improperly validates authentication for its VNC access service, allowing access with insufficient password verification. This could allow an attacker to gain unauthorized remote access and potentially compromise system confidentiality, integrity, or availability.

Affected products

• Siemens Sinumerik 828d ppu.4: before V4.95 SP5 (fixed in V4.95 SP5)
• Siemens Sinumerik 828d ppu.5: before V5.25 SP1 (fixed in V5.25 SP1)
• Siemens Sinumerik 840d Sl: before V4.95 SP5 (fixed in V4.95 SP5)
• Siemens Sinumerik Mc: before V1.25 SP1 (fixed in V1.25 SP1)
• Siemens Sinumerik Mc v1.15: before V1.15 SP5 (fixed in V1.15 SP5)
• Siemens Sinumerik One: before V6.25 SP1 (fixed in V6.25 SP1)
• Siemens Sinumerik One v6.15: before V6.15 SP5 (fixed in V6.15 SP5)

Published 2025-08-12. Last modified 2026-06-17.