CVE-2025-40566 Security feature bypass in SIMATIC PCS neo V4.1

High 8.7 Published Updated

Attackers can reuse session tokens after logout to hijack legitimate user sessions in Siemens SIMATIC PCS neo.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2025-40566?

CVE-2025-40566 is a high-severity vulnerability in Siemens SIMATIC PCS neo V4.1, published on 13 May 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-613

Which versions are affected by CVE-2025-40566?

It affects 1 product.

Products include Siemens Simatic Pcs Neo.

How do I fix CVE-2025-40566?

No fix has been published for CVE-2025-40566 yet. Limit exposure of the affected software until one is available.

Is CVE-2025-40566 being exploited?

There is no known exploitation of CVE-2025-40566 in the wild and no public exploit code.

Sources

Also known as GHSA-wmm5-59wm-x34p.

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