On October 13, 2026, Microsoft released .NET 11 Release Candidate 2 alongside servicing patches for .NET 10, 9, and 8, collectively addressing approximately 40 to 44 CVEs, primarily related to remote code execution vulnerabilities. This release marks a significant moment as it offers a production-ready preview of .NET 11, which is expected to launch in November 2026, and comes with a go-live license that allows developers to use it in real-world applications. Microsoft advises developers to immediately patch their applications on .NET 8, 9, and 10 due to the large number of security fixes and the imminent end of support for .NET 8 and 9 within months. The updates also include various enhancements across libraries and frameworks, positioning .NET 11 as a more robust and feature-rich option moving forward

.NET 11 RC2 and October 2026 Security Patches: 40+ CVEs Fix Across .NET 8, 9, and 10

Microsoft shipped four .NET tracks on a single coordinated day, October 13, 2026, pairing .NET 11 Release Candidate 2 with three servicing patches: .NET 10.0.13, .NET 9.0.21, and .NET 8.0.32. The RC2 carries a go-live license and arrives just weeks before .NET 11's expected November stable launch, making it a production-testable preview. Each fixed channel absorbed an unusually large security batch of roughly 40 to 44 new CVEs, dominated by remote code execution flaws and a Microsoft QUIC RCE affecting all three. With .NET 8 and .NET 9 both exiting support within months, Microsoft's guidance is to patch immediately and budget engineering effort toward .NET 10.

.NET 11 RC2 and October 2026 Security Patches: 40+ CVEs Fix Across .NET 8, 9, and 10 @ NT Compatible