CVE-2026-21218: CWE-166: Improper Handling of Missing Special Element in Microsoft .NET 10.0
Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-21218) affects Microsoft .NET 10.0 and is categorized under CWE-166, which relates to improper handling of missing special elements. The issue enables an attacker without privileges or user interaction to spoof network communications, potentially misleading systems or users. The CVSS 3.1 vector indicates network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on integrity. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
An attacker can exploit this vulnerability to spoof network communications, potentially causing integrity violations in affected systems running .NET 10.0. There is no impact on confidentiality or availability reported. No known active exploits have been observed in the wild.
Mitigation Recommendations
Microsoft has released an official fix for this vulnerability. Users and administrators should apply the security update provided by Microsoft as detailed in their advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21218 to remediate this issue.
CVE-2026-21218: CWE-166: Improper Handling of Missing Special Element in Microsoft .NET 10.0
Description
Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-21218) affects Microsoft .NET 10.0 and is categorized under CWE-166, which relates to improper handling of missing special elements. The issue enables an attacker without privileges or user interaction to spoof network communications, potentially misleading systems or users. The CVSS 3.1 vector indicates network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on integrity. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
An attacker can exploit this vulnerability to spoof network communications, potentially causing integrity violations in affected systems running .NET 10.0. There is no impact on confidentiality or availability reported. No known active exploits have been observed in the wild.
Mitigation Recommendations
Microsoft has released an official fix for this vulnerability. Users and administrators should apply the security update provided by Microsoft as detailed in their advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21218 to remediate this issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-11T21:02:05.731Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21218","vendor":"Microsoft"}]
Threat ID: 698b75fd4b57a58fa1209fa0
Added to database: 2/10/2026, 6:16:29 PM
Last enriched: 5/12/2026, 5:09:51 AM
Last updated: 5/22/2026, 7:49:34 AM
Views: 416
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