CVE-2026-62886: .NET Elevation of Privilege Vulnerability

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-11 · updated 2026-10-30
Weakness: CWE-190

Description

Integer overflow or wraparound in .NET allows an unauthorized attacker to elevate privileges locally.

Affected products

Microsoft .NET: from 8.0.0 before 8.0.30; from 9.0.0 before 9.0.19; from 10.0.0 before 10.0.11 — fixed in 8.0.30, 9.0.19, 10.0.11
Microsoft Visual Studio 2022 version 17.14: from 17.14.0 before 17.14.38 — fixed in 17.14.38
Microsoft Visual Studio 2026 version 18.9: from 18.8.0 before 18.8.3 — fixed in 18.8.3
Microsoft .NET Framework 3.5: from 3.5.0 before 2.0.50727.8987 AND 3.0.30729.8982 — fixed in 2.0.50727.8987 AND 3.0.30729.8982
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2: from 3.0.0.0 before 2.0.50727.9073 AND 3.0.30729.9070 AND 4.7.4150.0 — fixed in 2.0.50727.9073 AND 3.0.30729.9070 AND 4.7.4150.0
Microsoft .NET Framework 3.5 AND 4.7.2: from 4.7.0 before 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4145.0 — fixed in 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4145.0
Microsoft .NET Framework 3.5 AND 4.8: from 4.8.0 before 2.0.50727.9073 AND 3.0.30729.9070 AND 4.8.4811.0 — fixed in 2.0.50727.9073 AND 3.0.30729.9070 AND 4.8.4811.0
Microsoft .NET Framework 3.5 AND 4.8.1: from 4.8.1 before 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0 — fixed in 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2: from 4.7.0 before 4.7.4145.0 — fixed in 4.7.4145.0
Microsoft .NET Framework 4.8: from 4.8.0 before 4.8.4806.0 — fixed in 4.8.4806.0
Microsoft .NET Framework 4.8.1: from 4.8.0.0 before 4.8.9347.0 — fixed in 4.8.9347.0
Microsoft Visual Studio 2026 version 18.8: from 18.0 before 18.8.3 — fixed in 18.8.3

How to fix

Upgrade to a fixed version: Microsoft .NET 8.0.30, 9.0.19, 10.0.11; Microsoft Visual Studio 2022 version 17.14 17.14.38; Microsoft Visual Studio 2026 version 18.9 18.8.3; Microsoft .NET Framework 3.5 2.0.50727.8987 AND 3.0.30729.8982; Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 2.0.50727.9073 AND 3.0.30729.9070 AND 4.7.4150.0; Microsoft .NET Framework 3.5 AND 4.7.2 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4145.0; Microsoft .NET Framework 3.5 AND 4.8 2.0.50727.9073 AND 3.0.30729.9070 AND 4.8.4811.0; Microsoft .NET Framework 3.5 AND 4.8.1 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0; Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 4.7.4145.0; Microsoft .NET Framework 4.8 4.8.4806.0; Microsoft .NET Framework 4.8.1 4.8.9347.0; Microsoft Visual Studio 2026 version 18.8 18.8.3. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62886

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