Heap-based Buffer Overflow in .NET and Visual Studio by Microsoft
CVE-2026-69439

8.8HIGH

Key Information:

Vendor

Microsoft
Status
.net 10.0
.net 11.0
.net 8.0
.net 9.0
Vendor
CVE Published:
8 September 2026

What is CVE-2026-69439?

A heap-based buffer overflow vulnerability exists in .NET and Visual Studio, allowing unauthorized attackers to potentially escalate their privileges over a network. This security concern necessitates immediate attention, as it could be exploited to gain elevated access rights, putting systems and sensitive data at risk. Users of affected Microsoft software should apply available patches to mitigate the risks associated with this vulnerability.

Affected Version(s)

.NET 10.0 10.0.0 < 10.0.12

.NET 11.0 11.0.0 < 11.0 RC1

.NET 8.0 8.0.0 < 8.0.31

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.