--- 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: '2026-10-14' sourceUpdated: '2026-10-14T04:18:32.693' 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' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70179' - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-70179.json - url: 'https://access.redhat.com/security/cve/CVE-2026-70179' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2548790' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-70179' - url: 'https://access.redhat.com/errata/RHSA-2026:86195' - url: 'https://access.redhat.com/errata/RHSA-2026:86168' - url: 'https://access.redhat.com/errata/RHSA-2026:86172' - url: 'https://access.redhat.com/errata/RHSA-2026:86192' - url: 'https://access.redhat.com/errata/RHSA-2026:86594' - url: 'https://access.redhat.com/errata/RHSA-2026:86170' - url: 'https://access.redhat.com/errata/RHSA-2026:86193' - url: 'https://access.redhat.com/errata/RHSA-2026:86169' - url: 'https://access.redhat.com/errata/RHSA-2026:86171' - url: 'https://access.redhat.com/errata/RHSA-2026:88474' - url: 'https://access.redhat.com/errata/RHSA-2026:88424' - url: 'https://access.redhat.com/errata/RHSA-2026:88425' - url: 'https://access.redhat.com/errata/RHSA-2026:88422' tags: - nvd - ghsa - nuget - cve.org - csaf - vex - red-hat aliases: - GHSA-vrrp-6v32-2p8g ecosystem: nuget ingestedAt: '2026-10-13T19:43:29.020Z' ssvc: exploitation: none automatable: 'no' technicalImpact: total timestamp: '2026-10-08T00:00:00+00:00' epss: 0.00629 epssPercentile: 0.49949 --- ## 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 ## Vendor advisories - **RHSA-2026:86195** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86195) - **RHSA-2026:86168** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86168) - **RHSA-2026:86172** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86172) - **RHSA-2026:86192** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86192) - **RHSA-2026:86594** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:86594) - **RHSA-2026:86170** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86170) - **RHSA-2026:86193** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86193) - **RHSA-2026:86169** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86169) - **RHSA-2026:86171** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86171) - **RHSA-2026:88474** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88474) - **RHSA-2026:88424** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88424) - **RHSA-2026:88425** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88425) - **RHSA-2026:88422** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88422)