.NET Framework
CVE-2026-97801 — .NET Framework Tampering Vulnerability
Executive Summary
Improper validation of specified type of input in .NET Framework allows an unauthorized attacker to perform tampering over a network.
Overview
7.5
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
None
INTEGRITY
High
AVAILABILITY
None
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.5
EPSS Score
No EPSS score available for this CVE.
View on FIRST.orgAffected Products
27 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 version 1607 | 5126868 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016 | 5126868 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2019 | 5127666 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 version 1809 | 5127666 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 1809 | 5127685 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 21H2 | 5127683 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 22H2 | 5127683 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019 | 5127685 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022 | 5127687 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 21H2 | 5127689 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 22H2 | 5127689 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 23H2 | 5127692 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 24H2 | 5127690 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 25H2 | 5127690 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 26H2 | 5127694 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022 | 5127693 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025 | 5127690 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 on Windows 11 version 26H1 | 5127696 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 on Windows Server 2012 | 5127660 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 3.5 on Windows Server 2012 R2 | 5127664 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 | 5127667 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2 | 5127668 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 4.8 on Windows 10 version 1607 | 5127684 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 4.8 on Windows Server 2012 | 5127686 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 4.8 on Windows Server 2012 R2 | 5127688 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 4.8 on Windows Server 2016 | 5127684 (Security Update) |
Important | Tampering | Maybe |
| Microsoft .NET Framework 4.8.1 on Windows 11 version 26H1 | 5127691 (Security Update) |
Important | Tampering | Maybe |
Patches
19 patches
| Article | Type | Restart |
|---|---|---|
5126868 |
Security Update | Maybe |
5127666 |
Security Update | Maybe |
5127685 |
Security Update | Maybe |
5127683 |
Security Update | Maybe |
5127687 |
Security Update | Maybe |
5127689 |
Security Update | Maybe |
5127692 |
Security Update | Maybe |
5127690 |
Security Update | Maybe |
5127694 |
Security Update | Maybe |
5127693 |
Security Update | Maybe |
5127696 |
Security Update | Maybe |
5127660 |
Security Update | Maybe |
5127664 |
Security Update | Maybe |
5127667 |
Security Update | Maybe |
5127668 |
Security Update | Maybe |
5127684 |
Security Update | Maybe |
5127686 |
Security Update | Maybe |
5127688 |
Security Update | Maybe |
5127691 |
Security Update | Maybe |
Exploits & PoC
No public exploit or PoC has been linked for this CVE yet. When available, references are sourced from public repositories and may be unverified or non-functional — review carefully before use.
Detection Rules
No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.
Acknowledgments
Microsoft has not published researcher acknowledgments for this CVE, or they are not yet reflected in our data source. Check the MSRC advisory directly for the most current credit information.
References
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