CVE-2026-62871: .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-787

Description

Out-of-bounds write in .NET allows an unauthorized attacker to execute code 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 8.0 runtime: from 8.0.0 before 8.0.30 — fixed in 8.0.30
Microsoft .NET 9.0 runtime: from 9.0.0 before 9.0.19 — fixed in 9.0.19
Microsoft Visual Studio 2026 version 18.8: from 18.0 before 18.8.3 — fixed in 18.8.3
Microsoft Visual Studio 2022 version 17.14: from 17.14.0 before 17.14.38 — fixed in 17.14.38

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 8.0 runtime 8.0.30; Microsoft .NET 9.0 runtime 9.0.19; Microsoft Visual Studio 2026 version 18.8 18.8.3; Microsoft Visual Studio 2022 version 17.14 17.14.38. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62871

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