CVE-2025-59287

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

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Potential Mitigations

• Make fields transient to protect them from deserialization.
• An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59287
• https://hawktrace.com/blog/CVE-2025-59287
• https://www.bleepingcomputer.com/news/security/cisa-orders-feds-to-patch-windows-server-wsus-flaw-exploited-in-attacks/
• https://www.vicarius.io/vsociety/posts/cve-2025-59287-detection-script-rce-vulnerability-in-windows-server-update-service
• https://www.vicarius.io/vsociety/posts/cve-2025-59287-mitigation-script-rce-vulnerability-in-windows-server-update-service
• https://gist.github.com/hawktrace/880b54fb9c07ddb028baaae401bd3951
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59287