Review reviewHigh

CVE-2026-50649

Microsoft .NET 8.0, .NET 9.0, Microsoft .NET Framework 3.5

Deserialization of untrusted data in .NET allows an unauthorized attacker to execute code locally.

PRIORITY ASSESSMENT

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.92%

Technical severityCVSS 7.8

Deserialization of untrusted data in .NET allows an unauthorized attacker to execute code locally.

Product: Microsoft .NET 8.0, .NET 9.0, Microsoft .NET Framework 3.5
Affected versions: >= 8.0.0 < 8.0.29, >= 9.0.0 < 9.0.18, >= 3.5.0 < 2.0.50727.9182 & 3.0.30729.9168, >= 4.7.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0, >= 4.8.0 < 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0, >= 4.8.1 < 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0, >= 4.7.0 < 4.7.4143.0, >= 4.8.0 < 4.8.4803.0, >= 4.8.0.0 < 4.8.9340.0, >= 18.0 < 18.7.4, 4.8.1, 4.8, 4.6.2, 4.7, 4.7.1, 4.7.2, 3.5, >= 18.7.0 < 18.7.4
Fixed versions: 8.0.29, 9.0.18, 18.7.4

Confirm exposure before applying a vendor-supported change.

1
Identify
Confirm that Microsoft .NET 8.0, .NET 9.0, Microsoft .NET Framework 3.5 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.