.NET Core Remote Code Execution Vulnerability
Priority HIGH 66Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat.
Summary
.NET Core Remote Code Execution Vulnerability
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.30096 98th percentileScored 2026-11-07
Fix Fixed .NET Core 2.1 (Microsoft): publication.NET Core 3.1 (Microsoft): publication+10 more productsRed Hat: 6 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | .NET Core 2.1 | 2.1 to before publication | publication | Patch available | CNA |
| Microsoft | .NET Core 3.1 | 3.1 to before publication | publication | Patch available | CNA |
| Microsoft | .NET 5.0 | 5.0.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3) | 16.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8) | 15.9.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6) | 16.0.0 to before publication | publication | Patch available | CNA |
| Microsoft | Visual Studio 2019 for Mac | 8.0.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Visual Studio 2019 version 16.8 (includes 16.0 - 16.7) | 16.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) | 15.0.0 to before publication | publication | Patch available | CNA |
| Microsoft | PowerShell Core 7.1 | 7.1.0 to before publication | publication | Patch available | CNA |
| Microsoft | PowerShell Core 7.0 | 7.0.0 to before publication | publication | Patch available | CNA |
| — | System.Text.Encodings.Web (NuGet) | 4.0.0 to before 4.5.1 | 4.5.1 | Patch available | GHSA-ghhp-997w-qr28 |
| — | System.Text.Encodings.Web (NuGet) | 4.6.0 to before 4.7.2 | 4.7.2 | Patch available | GHSA-ghhp-997w-qr28 |
| — | System.Text.Encodings.Web (NuGet) | 5.0.0 to before 5.0.1 | 5.0.1 | Patch available | GHSA-ghhp-997w-qr28 |
- .NET Core 2.1 VendorMicrosoft Affected 2.1 to before publication Fixed in publication Patch available CNA
- .NET Core 3.1 VendorMicrosoft Affected 3.1 to before publication Fixed in publication Patch available CNA
- .NET 5.0 VendorMicrosoft Affected 5.0.0 to before publication Fixed in publication Patch available CNA
- Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3) VendorMicrosoft Affected 16.0 to before publication Fixed in publication Patch available CNA
- Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8) VendorMicrosoft Affected 15.9.0 to before publication Fixed in publication Patch available CNA
- Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6) VendorMicrosoft Affected 16.0.0 to before publication Fixed in publication Patch available CNA
- Visual Studio 2019 for Mac VendorMicrosoft Affected 8.0.0 to before publication Fixed in publication Patch available CNA
- Microsoft Visual Studio 2019 version 16.8 (includes 16.0 - 16.7) VendorMicrosoft Affected 16.0 to before publication Fixed in publication Patch available CNA
- Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) VendorMicrosoft Affected 15.0.0 to before publication Fixed in publication Patch available CNA
- PowerShell Core 7.1 VendorMicrosoft Affected 7.1.0 to before publication Fixed in publication Patch available CNA
- PowerShell Core 7.0 VendorMicrosoft Affected 7.0.0 to before publication Fixed in publication Patch available CNA
- System.Text.Encodings.Web (NuGet) Vendor— Affected 4.0.0 to before 4.5.1 Fixed in 4.5.1 Patch available GHSA-ghhp-997w-qr28
- System.Text.Encodings.Web (NuGet) Vendor— Affected 4.6.0 to before 4.7.2 Fixed in 4.7.2 Patch available GHSA-ghhp-997w-qr28
- System.Text.Encodings.Web (NuGet) Vendor— Affected 5.0.0 to before 5.0.1 Fixed in 5.0.1 Patch available GHSA-ghhp-997w-qr28
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:* | 5.0 to before 5.0.4 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:.net_core:*:*:*:*:*:*:*:* | 2.1 to before 2.1.28; 3.1 to before 3.1.15 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:powershell_core:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:powershell_core:7.1:*:*:*:*:*:*:* | 7.1 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:visual_studio_2019:*:*:*:*:*:*:*:* | 16.0 – 16.9 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:visual_studio_2019:-:*:*:*:*:macos:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* | 32 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 33 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
- cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:* Versions 5.0 to before 5.0.4 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:.net_core:*:*:*:*:*:*:*:* Versions 2.1 to before 2.1.28; 3.1 to before 3.1.15 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:powershell_core:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:powershell_core:7.1:*:*:*:*:*:*:* Versions 7.1 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:visual_studio_2019:*:*:*:*:*:*:*:* Versions 16.0 – 16.9 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:visual_studio_2019:-:*:*:*:*:macos:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
Remediation
- Fix · CNA .NET Core 2.1 (Microsoft) Fixed in publication
- Fix · CNA .NET Core 3.1 (Microsoft) Fixed in publication
- Fix · CNA .NET 5.0 (Microsoft) Fixed in publication
- Fix · CNA Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3) (Microsoft) Fixed in publication
- Fix · CNA Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8) (Microsoft) Fixed in publication
- Fix · CNA Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6) (Microsoft) Fixed in publication
- Fix · CNA Visual Studio 2019 for Mac (Microsoft) Fixed in publication
- Fix · CNA Microsoft Visual Studio 2019 version 16.8 (includes 16.0 - 16.7) (Microsoft) Fixed in publication
- Fix · CNA Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) (Microsoft) Fixed in publication
- Fix · CNA PowerShell Core 7.1 (Microsoft) Fixed in publication
- Fix · CNA PowerShell Core 7.0 (Microsoft) Fixed in publication
- Fix · GHSA-ghhp-997w-qr28 System.Text.Encodings.Web (NuGet) Fixed in 4.5.1 Advisory →
- Fix · GHSA-ghhp-997w-qr28 System.Text.Encodings.Web (NuGet) Fixed in 4.7.2 Advisory →
- Fix · GHSA-ghhp-997w-qr28 System.Text.Encodings.Web (NuGet) Fixed in 5.0.1 Advisory →
Red Hat 6 advisories
- RHSA-2021:0794 Released 2021-03-09 · Red Hat rating Important.NET 5.0 on Red Hat Enterprise Linux security and bugfix update
- .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.4-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.4-1.el7_9, rh-dotnet50-dotnet-5.0.104-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.4-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.4-1.el7_9, rh-dotnet50-dotnet-5.0.104-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet50-aspnetcore-runtime-5.0-5.0.4-1.el7_9, rh-dotnet50-aspnetcore-targeting-pack-5.0-5.0.4-1.el7_9, rh-dotnet50-dotnet-5.0.104-1.el7_9 +8
- RHSA-2021:0793 Released 2021-03-09 · Red Hat rating Important.NET Core on RHEL 8 security and bugfix update
- Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-5.0-5.0.4-1.el8_3, aspnetcore-targeting-pack-5.0-5.0.4-1.el8_3, dotnet-5.0.104-1.el8_3 +9
- RHSA-2021:0787 Released 2021-03-09 · Red Hat rating Important.NET Core 2.1 on Red Hat Enterprise Linux security and bugfix update
- .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) rh-dotnet21-2.1-25.el7_9, rh-dotnet21-dotnet-2.1.522-1.el7_9, rh-dotnet21-dotnet-host-2.1.26-1.el7_9 +4
- .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet21-2.1-25.el7_9, rh-dotnet21-dotnet-2.1.522-1.el7_9, rh-dotnet21-dotnet-host-2.1.26-1.el7_9 +4
- .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet21-2.1-25.el7_9, rh-dotnet21-dotnet-2.1.522-1.el7_9, rh-dotnet21-dotnet-host-2.1.26-1.el7_9 +4
Show 3 more Red Hat advisories
- RHSA-2021:0789 Released 2021-03-09 · Red Hat rating Important.NET Core 3.1 on Red Hat Enterprise Linux security and bugfix update
- .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.13-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.13-1.el7_9, rh-dotnet31-dotnet-3.1.113-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.13-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.13-1.el7_9, rh-dotnet31-dotnet-3.1.113-1.el7_9 +8
- .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet31-aspnetcore-runtime-3.1-3.1.13-1.el7_9, rh-dotnet31-aspnetcore-targeting-pack-3.1-3.1.13-1.el7_9, rh-dotnet31-dotnet-3.1.113-1.el7_9 +8
- RHSA-2021:0788 Released 2021-03-09 · Red Hat rating Importantdotnet security and bugfix update
- Red Hat Enterprise Linux AppStream (v. 8) dotnet-2.1.522-1.el8_3, dotnet-host-fxr-2.1-2.1.26-1.el8_3, dotnet-runtime-2.1-2.1.26-1.el8_3 +2
- RHSA-2021:0790 Released 2021-03-09 · Red Hat rating Importantdotnet3.1 security and bugfix update
- Red Hat Enterprise Linux AppStream (v. 8) aspnetcore-runtime-3.1-3.1.13-1.el8_3, aspnetcore-targeting-pack-3.1-3.1.13-1.el8_3, dotnet-apphost-pack-3.1-3.1.13-1.el8_3 +6
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) | Fixed | RHSA-2021:0787, RHSA-2021:0789, RHSA-2021:0794 |
| .NET Core on Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2021:0787, RHSA-2021:0789, RHSA-2021:0794 |
| .NET Core on Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2021:0787, RHSA-2021:0789, RHSA-2021:0794 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2021:0788, RHSA-2021:0790, RHSA-2021:0793 |
Timeline
- 2026-10-02 Threatist record created from CVE-2021-26701
- 2026-10-03 Alias added: GHSA-ghhp-997w-qr28
References
Advisory 7
Other 13
- https://github.com/dotnet/announcements/issues/178
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S2AZOUKMCHT2WBHR7MYDTYXWOBHZW5P5
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TW3ZSJTTMZAFKGW7NJWTVVFZUYYU2SJZ
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UBOSSX7U6BSHV5RI74FCOW4ITJ5RRJR5
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WA5WQJVHUL5C4XMJTLY3C67R4WP35EF4
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XPUKFHIGP5YNJRRFWKDJ2XRS4WTFJNNK
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YLFATXASXW4OV2ZBSRP4G55HJH73QPBP
- https://lists.fedoraproject.org/archives/list/[email protected]/message/S2AZOUKMCHT2WBHR7MYDTYXWOBHZW5P5
- https://lists.fedoraproject.org/archives/list/[email protected]/message/TW3ZSJTTMZAFKGW7NJWTVVFZUYYU2SJZ
- https://lists.fedoraproject.org/archives/list/[email protected]/message/UBOSSX7U6BSHV5RI74FCOW4ITJ5RRJR5
- https://lists.fedoraproject.org/archives/list/[email protected]/message/WA5WQJVHUL5C4XMJTLY3C67R4WP35EF4
- https://lists.fedoraproject.org/archives/list/[email protected]/message/XPUKFHIGP5YNJRRFWKDJ2XRS4WTFJNNK
- https://lists.fedoraproject.org/archives/list/[email protected]/message/YLFATXASXW4OV2ZBSRP4G55HJH73QPBP
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Sources
- CVE-2021-26701 · CVE Program
- CVE-2021-26701 · NVD
- FIRST EPSS
- GHSA-ghhp-997w-qr28 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-26701 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences