Deserialization of Untrusted Data in .NET and Visual Studio - CVE-2026-50649

Vulnerability identifier: #VU138085

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-50649

CWE-ID: CWE-502

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local attacker to execute arbitrary code.

The vulnerability exists due to deserialization of untrusted data in .NET when processing untrusted serialized data. A local attacker can supply crafted serialized input to execute arbitrary code.

.NET
Visual Studio
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
dotnet8.0 (Red Hat package)
dotnet9.0 (Red Hat package)

Install security update from vendor's website.

.NET - addressed in versions 8.0.29, 9.0.18
Visual Studio - update to 17.12.22
dotnet8.0 (Red Hat package) - update to 8.0.130-1.el10_0
dotnet9.0 (Red Hat package) - update to 9.0.120-1.el10_0

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-50649

• Multiple vulnerabilities in Visual Studio
• Red Hat Enterprise Linux 10 update for .NET 8.0
• Red Hat Enterprise Linux 10 update for .NET 9.0