MSRC-CVE-2026-58649 — .NET Information Disclosure Vulnerability

Summary

Impact: Information Disclosure. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

What type of information could be disclosed by this vulnerability?
Successful exploitation could disclose developer-time hot reload data, including application metadata, intermediate language updates, debugging information, method names, string literals, and file paths.

Security updates
17.14.40 — https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes
8.0.130, 8.0.424 — https://support.microsoft.com/help/5126104
9.0.120, 9.0.317 — https://support.microsoft.com/help/5126105
18.9.3 — https://learn.microsoft.com/en-us/visualstudio/releases/2026/release-notes
10.0.111, 10.0.400 — https://support.microsoft.com/help/5126106

Vulnerabilities 1

Medium 6.5

CVE-2026-58649

.NET Information Disclosure Vulnerability

Origin validation error in .NET allows an unauthorized attacker to disclose information over a network.

Microsoft Microsoft Visual Studio 2022 version 17.14 .NET 9.0 runtime .NET 8.0 runtime Ubuntu Alpine

Sep 8, 2026

Revision history

2026-09-08 #1
Information published.

References

CVE-2026-58649 .NET Information Disclosure Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58649
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss