---
id: CVE-2026-70179
title: >-
  Authentication bypass by spoofing in ASP.NET Core allows an authorized
  attacker to elevate privileges over a network.
summary: >-
  Authentication bypass by spoofing in ASP.NET Core allows an authorized
  attacker to elevate privileges over a network.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-290
vendor: Microsoft
product: Microsoft.AspNetCore.Authentication.Negotiate
affected:
  - 'Microsoft.AspNetCore.Authentication.Negotiate >= 10.0.0, <= 10.0.12'
  - 'Microsoft.AspNetCore.Authentication.Negotiate >= 8.0.0, <= 8.0.31'
  - 'Microsoft.AspNetCore.Authentication.Negotiate >= 9.0.0, <= 9.0.20'
patched:
  - Microsoft.AspNetCore.Authentication.Negotiate 10.0.13
  - Microsoft.AspNetCore.Authentication.Negotiate 8.0.32
  - Microsoft.AspNetCore.Authentication.Negotiate 9.0.21
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T21:18:04.770'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70179'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70179'
    label: secure@microsoft.com
  - url: >-
      https://github.com/dotnet/aspnetcore/security/advisories/GHSA-vrrp-6v32-2p8g
  - url: 'https://github.com/dotnet/announcements/issues/458'
  - url: 'https://github.com/dotnet/aspnetcore/discussions/69794'
  - url: 'https://github.com/advisories/GHSA-vrrp-6v32-2p8g'
tags:
  - nvd
  - ghsa
  - nuget
aliases:
  - GHSA-vrrp-6v32-2p8g
ecosystem: nuget
ingestedAt: '2026-10-13T19:43:29.020Z'
---

## Overview

Authentication bypass by spoofing in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-70179)

Affected packages:

- `Microsoft.AspNetCore.Authentication.Negotiate >= 10.0.0, <= 10.0.12`
- `Microsoft.AspNetCore.Authentication.Negotiate >= 8.0.0, <= 8.0.31`
- `Microsoft.AspNetCore.Authentication.Negotiate >= 9.0.0, <= 9.0.20`

Patched in:

- `Microsoft.AspNetCore.Authentication.Negotiate 10.0.13`
- `Microsoft.AspNetCore.Authentication.Negotiate 8.0.32`
- `Microsoft.AspNetCore.Authentication.Negotiate 9.0.21`

Source: https://github.com/advisories/GHSA-vrrp-6v32-2p8g