CVE-2025-66631: Cslanet Csla .net

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

CSLA .NET is a framework designed for the development of reusable, object-oriented business layers for applications. Versions 5.5.4 and below allow the use of WcfProxy. WcfProxy uses the now-obsolete NetDataContractSerializer (NDCS) and is vulnerable to remote code execution during deserialization. This vulnerability is fixed in version 6.0.0. To workaround this issue, remove the WcfProxy in data portal configurations.

Affected products

• Cslanet Csla .net: before 6.0.0 (fixed in 6.0.0)

Published 2025-12-09. Last modified 2026-10-07.