CVE-2026-58649: CWE-346: Origin Validation Error in Microsoft .NET 10.0
Description
CVE-2026-58649 is an origin validation error vulnerability in Microsoft .NET 10.0 that allows unauthorized attackers to disclose information over a network. The vulnerability affects multiple versions of .NET, including 8.0.0, 9.0.0, 10.0.0, 11.0.0, and specific ranges in 17.x and 18.x versions. It has a CVSS 3.1 base score of 6.5, indicating medium severity. An official fix is available from Microsoft.
CVSS v3.1
Score 6.5medium
Affected software
Microsoft
.NET 10.0
Microsoft
.NET 11.0
Microsoft
.NET 8.0
Microsoft
.NET 9.0
Microsoft
Microsoft Visual Studio 2022 version 17.14
Microsoft
Microsoft Visual Studio 2026 version 18.9
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-58649) involves an origin validation error in Microsoft .NET 10.0 and related versions, which can be exploited by unauthorized attackers to disclose information over a network. The flaw is categorized under CWE-346 (Origin Validation Error). The CVSS 3.1 vector indicates network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, high confidentiality impact, no integrity or availability impact, and an official remediation level with confirmed fix. Microsoft has published an advisory confirming the vulnerability and providing an official fix.
Potential Impact
Exploitation of this vulnerability can lead to unauthorized disclosure of sensitive information over the network. There is no impact on integrity or availability. The medium severity score reflects the confidentiality impact without further system compromise or denial of service.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the vendor-provided patches as detailed in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58649 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-07-01T21:14:44.619Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58649","vendor":"Microsoft"}]
Threat ID: 6aa044c5acd9273b49fa5fdb
Added to database: 09/08/2026, 17:24:21 UTC
Last enriched: 10/16/2026, 20:39:48 UTC
Last updated: 10/23/2026, 15:12:03 UTC
Views: 84
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