ASP.NET Core

Microsoft Issues Out-of-Band .NET Security Updates Fixing Brotli Buffer Overflow and Other Flaws

Microsoft has released out-of-band security updates for .NET 10, .NET 9, and .NET 8 to address multiple vulnerabilities. The patches cover two newly identified issues and complete remediation for two additional flaws that received incomplete fixes during the October 13 monthly update cycle. One critical vulnerability, CVE-2026-111497, affects the Brotli compression library and can lead to information disclosure, denial of service, or privilege escalation when processing crafted compressed data. A second issue, CVE-2026-114148, enables local privilege escalation in Linux distribution packages for ASP.NET Core due to improper ownership handling. Microsoft also reissued fixes for remote code execution vulnerabilities CVE-2026-70197 and CVE-2026-102870. Organizations are advised to apply the updates immediately, including rebuilding and redistributing applications in container or embedded environments.