CVE-2025-40566: Siemens SIMATIC Pcs Neo

Critical severity, CVSS 9.8. EPSS: 0.5% chance of exploitation in the next 30 days.

A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions < V4.1 Update 3), SIMATIC PCS neo V5.0 (All versions < V5.0 Update 1). Affected products do not correctly invalidate user sessions upon user logout. This could allow a remote unauthenticated attacker, who has obtained the session token by other means, to re-use a legitimate user's session even after logout.

Affected products

• Siemens SIMATIC Pcs Neo: before 4.1 (fixed in 4.1); before 5.0 (fixed in 5.0); version 4.1 only; version 5.0 only

Published 2025-05-13. Last modified 2026-06-17.