Origin validation error in Microsoft products - CVE-2026-58649

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Main Vulnerability Database Vulnerabilities #VU147478

Origin validation error in Microsoft products - CVE-2026-58649

Published: September 8, 2026


Vulnerability identifier: #VU147478
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-58649
CWE-ID: CWE-346
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to an origin validation error in .NET when validating origins. A remote attacker can exploit the vulnerability to disclose sensitive information.

User interaction is required. Successful exploitation could expose developer-time hot reload data, including application metadata, intermediate language updates, debugging information, method names, string literals, and file paths.


Affected software

.NET
Visual Studio
.NET for macOS
.NET for Linux
Microsoft .NET Framework
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
dotnet8.0 (Red Hat package)
dotnet8.0
dotnet9.0 (Red Hat package)
dotnet9.0
dotnet10.0 (Red Hat package)
dotnet10.0
dotnet10 (Ubuntu package)
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for IBM z Systems
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
Ubuntu
Fedora

How to mitigate CVE-2026-58649

Install security update from vendor's website.

.NET - addressed in versions 8.0.130, 9.0.120
Visual Studio - update to 17.14.40
.NET for macOS - addressed in versions 8.0.130, 9.0.120
.NET for Linux - addressed in versions 8.0.130, 9.0.120
Microsoft .NET Framework - update to 10.0.111
dotnet8.0 (Red Hat package) - addressed in versions 8.0.131-1.el8_10, 8.0.131-1.el9_8, 8.0.131-1.el10_2, 8.0.132-1.el9_4, 8.0.132-1.el9_6, 8.0.132-1.el10_0
dotnet8.0 - addressed in versions 8.0.131-1.fc43, 8.0.131-1.fc44
dotnet9.0 (Red Hat package) - addressed in versions 9.0.121-1.el8_10, 9.0.121-1.el9_8, 9.0.122-1.el10_0
dotnet9.0 - addressed in versions 9.0.121-1.fc43, 9.0.121-1.fc44
dotnet10.0 (Red Hat package) - addressed in versions 10.0.112-1.el8_10, 10.0.112-1.el9_8, 10.0.112-1.el10_2
dotnet10.0 - addressed in versions 10.0.112-1.fc43, 10.0.112-1.fc44, 10.0.112-1.fc45
dotnet10 (Ubuntu package) - addressed in versions 8.0.31-0ubuntu1~22.04.1, 8.0.31-0ubuntu1~24.04.1, 8.0.131-0ubuntu1~22.04.1, 8.0.131-0ubuntu1~24.04.1, 8.0.131-8.0.31-0ubuntu1~22.04.1, 8.0.131-8.0.31-0ubuntu1~24.04.1, 10.0.12-0ubuntu1~24.04.1, 10.0.12-0ubuntu1~26.04.1, 10.0.112-0ubuntu1~24.04.1, 10.0.112-0ubuntu1~26.04.1, 10.0.112-10.0.12-0ubuntu1~24.04.1, 10.0.112-10.0.12-0ubuntu1~26.04.1

External References

Related Security Bulletins