---
id: CVE-2025-66631
title: >-
  CSLA .NET is a framework designed for the development of reusable,
  object-oriented business layers for applications
summary: >-
  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 …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: cslanet
product: csla_.net
affected:
  - csla_.net < 6.0.0
patched:
  - csla_.net 6.0.0
published: '2025-12-09'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T23:10:00.237'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-66631'
references:
  - url: 'https://github.com/MarimerLLC/csla/issues/4001'
    label: security-advisories@github.com
  - url: 'https://github.com/MarimerLLC/csla/pull/4018'
    label: security-advisories@github.com
  - url: 'https://github.com/MarimerLLC/csla/security/advisories/GHSA-wq34-7f4g-953v'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00674
epssPercentile: 0.50299
ingestedAt: '2026-09-30T23:29:32.482Z'
---

## Overview

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

- `csla_.net < 6.0.0`

## Remediation

Upgrade past the affected range:

- `csla_.net 6.0.0`