CVE-2026-35433: .NET Elevation of Privilege Vulnerability

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-12 · updated 2026-10-26
Weakness: CWE-20

Description

Improper input validation in .NET allows an unauthorized attacker to elevate privileges locally.

Affected products

Microsoft .NET: from 8.0.0 before 8.0.27; from 9.0.0 before 9.0.16; from 10.0.0 before 10.0.8 — fixed in 8.0.27, 9.0.16, 10.0.8
Microsoft .NET Framework: 4.8, 3.5, 4.8.1, 4.7.2
Microsoft .NET: from 10.0.0 before 10.0.8 — fixed in 10.0.8
Microsoft .NET 8.0: from 8.0.0 before 8.0.27 — fixed in 8.0.27
Microsoft .NET 9.0: from 9.0.0 before 9.0.16 — fixed in 9.0.16
Microsoft .NET Framework 3.5: from 3.5.0 before 4.8.9334.0 and 4.8.4802.0 — fixed in 4.8.9334.0 and 4.8.4802.0
Microsoft .NET Framework 3.5 AND 4.7.2: from 4.7.0 before 4.8.9334.0 and 4.8.4802.0 — fixed in 4.8.9334.0 and 4.8.4802.0
Microsoft .NET Framework 3.5 AND 4.8: from 4.8.0 before 4.8.9334.0 and 4.8.4802.0 — fixed in 4.8.9334.0 and 4.8.4802.0
Microsoft .NET Framework 3.5 AND 4.8.1: from 4.8.1 before 4.8.9334.0 and 4.8.4802.0 — fixed in 4.8.9334.0 and 4.8.4802.0
Microsoft .NET Framework 4.8: from 4.8.0 before 4.8.9334.0 and 4.8.4802.0 — fixed in 4.8.9334.0 and 4.8.4802.0

How to fix

Upgrade to a fixed version: Microsoft .NET 8.0.27, 9.0.16, 10.0.8; Microsoft .NET 10.0.8; Microsoft .NET 8.0 8.0.27; Microsoft .NET 9.0 9.0.16; Microsoft .NET Framework 3.5 4.8.9334.0 and 4.8.4802.0; Microsoft .NET Framework 3.5 AND 4.7.2 4.8.9334.0 and 4.8.4802.0; Microsoft .NET Framework 3.5 AND 4.8 4.8.9334.0 and 4.8.4802.0; Microsoft .NET Framework 3.5 AND 4.8.1 4.8.9334.0 and 4.8.4802.0; Microsoft .NET Framework 4.8 4.8.9334.0 and 4.8.4802.0. Check the vendor advisory for mitigations.

References

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