ASP.NET Core Elevation of Privilege Vulnerability

Summary

Authentication bypass by assumed-immutable data in ASP.NET Core allows an authorized attacker to elevate privileges over a network. Published in July 2026 Security Updates. MSRC exploitability: Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely.

Why it matters

Microsoft published this item through its Security Update Guide, making it part of Patch Tuesday triage for affected Windows, cloud, or application estates.

Operator check

Review the Microsoft Security Update Guide entry for CVE-2026-47303. Confirm whether ASP.NET Core is deployed, then apply the current security update or documented mitigation. CVSS score: 8.8.

Sources