Review reviewHigh

CVE-2026-47303

Microsoft .NET 10.0, .NET 8.0, .NET 9.0

Authentication bypass by assumed-immutable data in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

PRIORITY ASSESSMENT

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.74%

Technical severityCVSS 8.8

Authentication bypass by assumed-immutable data in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

Product: Microsoft .NET 10.0, .NET 8.0, .NET 9.0
Affected versions: >= 10.0.0 < 10.0.10, >= 8.0.0 < 8.0.29, >= 9.0.0 < 9.0.18, >= 17.12.0 < 17.12.22, >= 17.14.0 < 17.14.36, >= 18.0 < 18.7.4, >= 10.0.0 < 10.0.6, >= 18.7.0 < 18.7.4
Fixed versions: 8.0.29, 9.0.18, 10.0.6, 17.12.22, 17.14.36, 18.7.4

Confirm exposure before applying a vendor-supported change.

1
Identify
Confirm that Microsoft .NET 10.0, .NET 8.0, .NET 9.0 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.