[ CVE-2025-59287 · Published 14 Oct 2025 ]
Microsoft Windows Server Update Service (WSUS) Deserialization of Untrusted Data Vulnerability
Exploited · CISA KEV CVSS 9.8
EPSS 100%No fix listed yet
[ Why it matters ]Priority signals
- Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2025-10-24
- EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)
- Critical severity: CVSS 9.8
[ Description ]Official description
Deserialization of untrusted data in Windows Server Update Service allows an unauthorized attacker to execute code over a network.
CISA: Microsoft Windows Server Update Service (WSUS) contains a deserialization of untrusted data vulnerability that allows for remote code execution.
[ Fixes ]Fixes and patches
CISA required action (US federal deadline 14 Nov 2025): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.
[ References ]References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59287Vendor Advisory
- hawktrace.com/blog/CVE-2025-59287ExploitThird Party Advisory
- www.bleepingcomputer.com/news/security/cisa-orders-feds-to-patch-windows-server-wsus-fl…Press/Media Coverage
- www.vicarius.io/vsociety/posts/cve-2025-59287-detection-script-rce-vulnerability-in-win…Third Party Advisory
- www.vicarius.io/vsociety/posts/cve-2025-59287-mitigation-script-rce-vulnerability-in-wi…MitigationThird Party Advisory
- gist.github.com/hawktrace/880b54fb9c07ddb028baaae401bd3951Third Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalogThird Party AdvisoryUS Government Resource