CVE-2025-66631: CSLA .NET is a framework designed for the development of reusable, object-oriented business layers for applica

Q: How do I fix CVE-2025-66631?

csla .net: upgrade to 6.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-66631 being exploited?

CVE-2025-66631 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-66631 affect?

CVE-2025-66631 affects csla .net. Severity is critical (CVSS 9.8). 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

Q: How urgent is CVE-2025-66631?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2025-66631 is a critical-severity flaw (CVSS 9.8) affecting csla .net. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-502
Published	2025-12-09
Last modified	2026-10-07

Publisher (CNA): GitHub, Inc. · Vendor: cslanet

Last updated 2026-10-07 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-12-09 16:18 UTCPublished CVE record published
2026-10-07 20:10 UTCUpdated Record last modified

cslanet csla .net UPGRADE

Affected: < 6.0.0

Fixed in: 6.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy csla-.net || rpm -q csla-.net || csla-.net --version

2. UPGRADE to 6.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade csla-.net

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade csla-.net

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-66631?

csla .net: upgrade to 6.0.0. Exact commands for each OS are on this page.

Is CVE-2025-66631 being exploited?

CVE-2025-66631 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-66631 affect?

CVE-2025-66631 affects csla .net. Severity is critical (CVSS 9.8). 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

How urgent is CVE-2025-66631?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

References

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