CVE-2025-59287
Microsoft Windows Server Update Service (WSUS) Deserialization of Untrusted Data Vulnerability
IN CISA KEV
Deserialization of untrusted data in Windows Server Update Service allows an unauthorized attacker to execute code over a network.
- Vendor
- Microsoft
- Product
- Windows
- CVSS 3.1
- 9.8 (critical), scored by secure@microsoft.comCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-502
- Published
- 2025-10-14
- NVD modified
- 2026-06-17
- NVD status
- Analyzed
CISA KEV
- Date added
- 2025-10-24
- Due date
- 2025-11-14
- Ransomware use
- Unknown
- Required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
EPSS
100% chance of exploitation in the next 30 days (percentile 99th)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
References
- msrc.microsoft.com (Vendor Advisory)
- www.bleepingcomputer.com (Press/Media Coverage)
- www.vicarius.io (Third Party Advisory)
- www.vicarius.io (Mitigation, Third Party Advisory)
- gist.github.com (Third Party Advisory)
- www.cisa.gov (Third Party Advisory, US Government Resource)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.