CVE-2025-59287 Microsoft Windows Server Update Service (WSUS) Deserialization of Untrusted Data

Exploited in the wild Critical 9.8 Published 14 Oct 2025 Updated 26 Feb 2026

An unauthorized attacker can execute arbitrary code remotely via deserialization in Windows Server Update Service.

Exploited in the wild: Since 24 Oct 2025
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-59287?

CVE-2025-59287 is a critical unsafe deserialization vulnerability in Microsoft Windows Server 2012, published on 14 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Deserialization of untrusted data in Windows Server Update Service allows an unauthorized attacker to execute code over a network.

Weakness: CWE-502

Which versions are affected by CVE-2025-59287?

It affects 6 products.

Products include Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2022 23h2, Microsoft Windows Server 2025.

How do I fix CVE-2025-59287?

No fix has been published for CVE-2025-59287 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 14 Nov 2025.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2025-59287 being exploited?

Yes. Attackers have exploited CVE-2025-59287 in the wild since at least 24 Oct 2025.

Public exploit code: 1 Metasploit module, 1 Nuclei template and 23 proofs of concept on GitHub.

All Microsoft Windows Server 2012 vulnerabilities

Sources

Also known as GHSA-943j-4893-6rfq.