Is CVE-2025-66631 in the CISA KEV catalog?

No. CVE-2025-66631 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2025-66631?

CVE-2025-66631 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2025-66631?

CVE-2025-66631 has an EPSS score of 0.56% (42th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2025-66631

CRITICAL

9.8

CVSS v3

NVD

Description

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.

CWE-502Deserialization of Untrusted Data

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.56%probability of exploitation in 30 days

42ndpercentile

Moderate risk: more likely to be exploited than 42% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-03-25.