Read the docs
TI-2026-34877 Aliases CVE-2026-47300GHSA-8prm-248r-h957

ASP.NET Core Elevation of Privilege Vulnerability

Priority MEDIUM 41CWE-303Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Privilege escalation
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from Microsoft.

Summary

Incorrect implementation of authentication algorithm in ASP.NET Core allows an authorized attacker to elevate privileges over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00778 56th percentileScored 2026-11-07
Fix Fixed .NET 10.0 runtime (Microsoft): 10.0.10.NET 8.0 runtime (Microsoft): 8.0.29+5 more productsRed Hat: 17 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Microsoft.NET 10.0 runtime10.0.0 to before 10.0.1010.0.10Patch availableCNA
Microsoft.NET 8.0 runtime8.0.0 to before 8.0.298.0.29Patch availableCNA
Microsoft.NET 9.0 runtime9.0.0 to before 9.0.189.0.18Patch availableCNA
MicrosoftMicrosoft Visual Studio 2022 version 17.1217.12.0 to before 17.12.2217.12.22Patch availableCNA
MicrosoftMicrosoft Visual Studio 2022 version 17.1417.14.0 to before 17.14.3617.14.36Patch availableCNA
MicrosoftMicrosoft Visual Studio 2026 version 18.718.0 to before 18.7.418.7.4Patch availableCNA
—Microsoft.AspNetCore.Authentication.Negotiate (NuGet)10.0.0 to before 10.0.1010.0.10Patch availableGHSA-8prm-248r-h957
—Microsoft.AspNetCore.Authentication.Negotiate (NuGet)9.0.0 to before 9.0.189.0.18Patch availableGHSA-8prm-248r-h957
—Microsoft.AspNetCore.Authentication.Negotiate (NuGet)8.0.0 to before 8.0.298.0.29Patch availableGHSA-8prm-248r-h957
  • .NET 10.0 runtime VendorMicrosoft Affected 10.0.0 to before 10.0.10 Fixed in 10.0.10 Patch available CNA
  • .NET 8.0 runtime VendorMicrosoft Affected 8.0.0 to before 8.0.29 Fixed in 8.0.29 Patch available CNA
  • .NET 9.0 runtime VendorMicrosoft Affected 9.0.0 to before 9.0.18 Fixed in 9.0.18 Patch available CNA
  • Microsoft Visual Studio 2022 version 17.12 VendorMicrosoft Affected 17.12.0 to before 17.12.22 Fixed in 17.12.22 Patch available CNA
  • Microsoft Visual Studio 2022 version 17.14 VendorMicrosoft Affected 17.14.0 to before 17.14.36 Fixed in 17.14.36 Patch available CNA
  • Microsoft Visual Studio 2026 version 18.7 VendorMicrosoft Affected 18.0 to before 18.7.4 Fixed in 18.7.4 Patch available CNA
  • Microsoft.AspNetCore.Authentication.Negotiate (NuGet) Vendor— Affected 10.0.0 to before 10.0.10 Fixed in 10.0.10 Patch available GHSA-8prm-248r-h957
  • Microsoft.AspNetCore.Authentication.Negotiate (NuGet) Vendor— Affected 9.0.0 to before 9.0.18 Fixed in 9.0.18 Patch available GHSA-8prm-248r-h957
  • Microsoft.AspNetCore.Authentication.Negotiate (NuGet) Vendor— Affected 8.0.0 to before 8.0.29 Fixed in 8.0.29 Patch available GHSA-8prm-248r-h957

CPE configurations NVD · 7

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*8.0.0 to before 8.0.29; 9.0.0 to before 9.0.18VulnerableMicrosoft
cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*not specified by NVDRunning onApple
cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*not specified by NVDRunning onLinux
cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*not specified by NVDRunning onMicrosoft
cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*10.0.0 to before 10.0.6VulnerableMicrosoft
cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:*:*:*17.12.0 to before 17.12.22; 17.14.0 to before 17.14.36VulnerableMicrosoft
cpe:2.3:a:microsoft:visual_studio_2026:*:*:*:*:*:*:*:*18.7.0 to before 18.7.4VulnerableMicrosoft
  • cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:* Versions 8.0.0 to before 8.0.29; 9.0.0 to before 9.0.18 Vulnerable ·Microsoft
  • cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Apple
  • cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Linux
  • cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Microsoft
  • cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:* Versions 10.0.0 to before 10.0.6 Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:*:*:* Versions 17.12.0 to before 17.12.22; 17.14.0 to before 17.14.36 Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:visual_studio_2026:*:*:*:*:*:*:*:* Versions 18.7.0 to before 18.7.4 Vulnerable ·Microsoft

Remediation

  • Fix · CNA .NET 10.0 runtime (Microsoft) Fixed in 10.0.10
  • Fix · CNA .NET 8.0 runtime (Microsoft) Fixed in 8.0.29
  • Fix · CNA .NET 9.0 runtime (Microsoft) Fixed in 9.0.18
  • Fix · CNA Microsoft Visual Studio 2022 version 17.12 (Microsoft) Fixed in 17.12.22
  • Fix · CNA Microsoft Visual Studio 2022 version 17.14 (Microsoft) Fixed in 17.14.36
  • Fix · CNA Microsoft Visual Studio 2026 version 18.7 (Microsoft) Fixed in 18.7.4
  • Fix · GHSA-8prm-248r-h957 Microsoft.AspNetCore.Authentication.Negotiate (NuGet) Fixed in 10.0.10 Advisory →
  • Fix · GHSA-8prm-248r-h957 Microsoft.AspNetCore.Authentication.Negotiate (NuGet) Fixed in 9.0.18 Advisory →
  • Fix · GHSA-8prm-248r-h957 Microsoft.AspNetCore.Authentication.Negotiate (NuGet) Fixed in 8.0.29 Advisory →

Red Hat 17 advisories

  • RHSA-2026:58570 Released 2026-08-24 · Red Hat rating Important
    .NET 9.0 security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) dotnet-sdk-9.0-source-built-artifacts-9.0.120-1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) aspnetcore-runtime-9.0-9.0.19-1.el9_6, aspnetcore-runtime-dbg-9.0-9.0.19-1.el9_6, aspnetcore-targeting-pack-9.0-9.0.19-1.el9_6 +12
  • RHSA-2026:58569 Released 2026-08-24 · Red Hat rating Important
    .NET 8.0 security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) dotnet-sdk-8.0-source-built-artifacts-8.0.130-1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) aspnetcore-runtime-8.0-8.0.30-1.el9_6, aspnetcore-runtime-dbg-8.0-8.0.30-1.el9_6, aspnetcore-targeting-pack-8.0-8.0.30-1.el9_6 +9
  • RHSA-2026:58568 Released 2026-08-24 · Red Hat rating Important
    .NET 8.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) aspnetcore-runtime-8.0-8.0.30-1.el9_4, aspnetcore-runtime-dbg-8.0-8.0.30-1.el9_4, aspnetcore-targeting-pack-8.0-8.0.30-1.el9_4 +11
Show 14 more Red Hat advisories
  • RHSA-2026:58567 Released 2026-08-24 · Red Hat rating Important
    .NET 9.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) aspnetcore-runtime-9.0-9.0.19-1.el10_0, aspnetcore-runtime-dbg-9.0-9.0.19-1.el10_0, aspnetcore-targeting-pack-9.0-9.0.19-1.el10_0 +12
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) dotnet-sdk-9.0-source-built-artifacts-9.0.120-1.el10_0
  • RHSA-2026:58566 Released 2026-08-24 · Red Hat rating Important
    .NET 8.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) aspnetcore-runtime-8.0-8.0.30-1.el10_0, aspnetcore-runtime-dbg-8.0-8.0.30-1.el10_0, aspnetcore-targeting-pack-8.0-8.0.30-1.el10_0 +9
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) dotnet-sdk-8.0-source-built-artifacts-8.0.130-1.el10_0
  • RHSA-2026:42145 Released 2026-07-20 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images aspnetcore-runtime-8.0-8.0.29-2.1.hum1@aarch64, aspnetcore-runtime-8.0-8.0.29-2.1.hum1@x86_64, aspnetcore-runtime-dbg-8.0-8.0.29-2.1.hum1@aarch64 +22
  • RHSA-2026:41898 Released 2026-07-20 · Red Hat rating Important
    .NET 10.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) aspnetcore-runtime-10.0-10.0.10-1.el9_8, aspnetcore-runtime-dbg-10.0-10.0.10-1.el9_8, aspnetcore-targeting-pack-10.0-10.0.10-1.el9_8 +11
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-10.0-source-built-artifacts-10.0.110-1.el9_8
  • RHSA-2026:41896 Released 2026-07-20 · Red Hat rating Important
    .NET 9.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) aspnetcore-runtime-9.0-9.0.18-1.el9_8, aspnetcore-runtime-dbg-9.0-9.0.18-1.el9_8, aspnetcore-targeting-pack-9.0-9.0.18-1.el9_8 +11
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-9.0-source-built-artifacts-9.0.119-1.el9_8
  • RHSA-2026:41894 Released 2026-07-20 · Red Hat rating Important
    .NET 8.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) aspnetcore-runtime-8.0-8.0.29-1.el9_8, aspnetcore-runtime-dbg-8.0-8.0.29-1.el9_8, aspnetcore-targeting-pack-8.0-8.0.29-1.el9_8 +9
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-8.0-source-built-artifacts-8.0.129-1.el9_8
  • RHSA-2026:41901 Released 2026-07-20 · Red Hat rating Important
    .NET 8.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-8.0-8.0.29-1.el8_10, aspnetcore-runtime-dbg-8.0-8.0.29-1.el8_10, aspnetcore-targeting-pack-8.0-8.0.29-1.el8_10 +9
    • Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-8.0-source-built-artifacts-8.0.129-1.el8_10
  • RHSA-2026:41897 Released 2026-07-20 · Red Hat rating Important
    .NET 10.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) aspnetcore-runtime-10.0-10.0.10-1.el10_2, aspnetcore-runtime-dbg-10.0-10.0.10-1.el10_2, aspnetcore-targeting-pack-10.0-10.0.10-1.el10_2 +11
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-10.0-source-built-artifacts-10.0.110-1.el10_2
  • RHSA-2026:41900 Released 2026-07-20 · Red Hat rating Important
    .NET 10.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-10.0-10.0.10-1.el8_10, aspnetcore-runtime-dbg-10.0-10.0.10-1.el8_10, aspnetcore-targeting-pack-10.0-10.0.10-1.el8_10 +12
    • Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-10.0-source-built-artifacts-10.0.110-1.el8_10
  • RHSA-2026:41895 Released 2026-07-20 · Red Hat rating Important
    .NET 9.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) aspnetcore-runtime-9.0-9.0.18-1.el10_2, aspnetcore-runtime-dbg-9.0-9.0.18-1.el10_2, aspnetcore-targeting-pack-9.0-9.0.18-1.el10_2 +11
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-9.0-source-built-artifacts-9.0.119-1.el10_2
  • RHSA-2026:41893 Released 2026-07-20 · Red Hat rating Important
    .NET 8.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) aspnetcore-runtime-8.0-8.0.29-1.el10_2, aspnetcore-runtime-dbg-8.0-8.0.29-1.el10_2, aspnetcore-targeting-pack-8.0-8.0.29-1.el10_2 +9
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-8.0-source-built-artifacts-8.0.129-1.el10_2
  • RHSA-2026:41899 Released 2026-07-20 · Red Hat rating Important
    .NET 9.0 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-9.0-9.0.18-1.el8_10, aspnetcore-runtime-dbg-9.0-9.0.18-1.el8_10, aspnetcore-targeting-pack-9.0-9.0.18-1.el8_10 +11
    • Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-9.0-source-built-artifacts-9.0.119-1.el8_10
  • RHSA-2026:39952 Released 2026-07-15 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images dotnet-sdk-9.0-9.0.119-1.hum1@aarch64, dotnet-sdk-9.0-9.0.119-1.hum1@x86_64, dotnet-sdk-9.0-source-built-artifacts-9.0.119-1.hum1@aarch64 +10
  • RHSA-2026:26638 Released 2026-06-17 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images dotnet-sdk-10.0-10.0.109-1.hum1@aarch64, dotnet-sdk-10.0-10.0.109-1.hum1@x86_64, dotnet-sdk-10.0-source-built-artifacts-10.0.109-1.hum1@aarch64 +8

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:58569, RHSA-2026:58570
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:41893, RHSA-2026:41895, RHSA-2026:41897
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:41899, RHSA-2026:41900, RHSA-2026:41901
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:41894, RHSA-2026:41896, RHSA-2026:41898
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:58568
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:58566, RHSA-2026:58567
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:58569, RHSA-2026:58570
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:41899, RHSA-2026:41900, RHSA-2026:41901
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:41893, RHSA-2026:41895, RHSA-2026:41897
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:41894, RHSA-2026:41896, RHSA-2026:41898
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:58566, RHSA-2026:58567
Red Hat Hardened ImagesFixed RHSA-2026:26638, RHSA-2026:39952, RHSA-2026:42145

Microsoft

Microsoft's page for this CVE →

Impact
Elevation of Privilege
Exploited
No
Publicly disclosed
No
Exploitability
Exploitation Less Likely
ProductStatusPlan or fix
.NET 10.0 installed on LinuxFixed 10.0.10 · Security Update
.NET 10.0 installed on Mac OSFixed 10.0.10 · Security Update
.NET 8.0 installed on LinuxFixed 8.0.29 · Security Update
.NET 8.0 installed on Mac OSFixed 8.0.29 · Security Update
.NET 8.0 installed on WindowsFixed 8.0.29 · Security Update
.NET 9.0 installed on LinuxFixed 9.0.18 · Security Update
.NET 9.0 installed on Mac OSFixed 9.0.18 · Security Update
.NET 9.0 installed on WindowsFixed 9.0.18 · Security Update
Microsoft Visual Studio 2022 version 17.12Fixed 17.12.22 · Security Update
Microsoft Visual Studio 2022 version 17.14Fixed 17.14.36 · Security Update
Microsoft Visual Studio 2026 version 18.7Fixed 18.7.4 · Security Update

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-47300
  2. 2026-10-03 Alias added: GHSA-8prm-248r-h957
  3. 2026-10-28 Fix available: Microsoft/.NET 10.0 [email protected], Microsoft/.NET 8.0 [email protected], Microsoft/.NET 9.0 [email protected] · CNA

References

Patch 1

Advisory 1

Other 4

  • TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2023-19596 .NET and Visual Studio Denial of Service Vulnerability KEVCVSS 3.1HIGH 7.5
  • TI-2023-19588 Microsoft QUIC Denial of Service Vulnerability CVSS 3.1HIGH 7.5
  • TI-2024-14152 .NET and Visual Studio Denial of Service Vulnerability CVSS 3.1HIGH 7.5
  • TI-2021-08380 .NET Core Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
See all 129 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences