medium
6.1
CVE-2026-109476 json
ASP.NET Core Information Disclosure Vulnerability
published yesterday modified 17h ago also EUVD-2026-121560 , GHSA-xhj5-c3g8-pfj8
- cvss
- 6.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 50%
- public exploits
- 0
- none known
Summary
Improper encoding or escaping of output in ASP.NET Core allows an unauthorized attacker to disclose information over a network.
Patch / fix
- nuget Microsoft.AspNetCore.App.Runtime.linux-arm 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.linux-arm64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.linux-musl-x64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.linux-x64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.osx-arm64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.osx-x64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.win-arm64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.win-x64 8.0.34, 9.0.23, 10.0.15, 11.0.0
- nuget Microsoft.AspNetCore.App.Runtime.win-x86 8.0.34, 9.0.23, 10.0.15, 11.0.0
- Microsoft .NET 10.0 installed on Linux 10.0.15
- Microsoft .NET 10.0 installed on Mac OS 10.0.15
- Microsoft .NET 10.0 installed on Windows 10.0.15
- Microsoft .NET 11.0 installed on Linux 11.0.0
- Microsoft .NET 11.0 installed on Mac OS 11.0.0
- Microsoft .NET 11.0 installed on Windows 11.0.0
- Microsoft .NET 8.0 installed on Linux 8.0.34
- Microsoft .NET 8.0 installed on Mac OS 8.0.34
- Microsoft .NET 8.0 installed on Windows 8.0.34
- Microsoft .NET 9.0 installed on Linux 9.0.23
- Microsoft .NET 9.0 installed on Mac OS 9.0.23
- Microsoft .NET 9.0 installed on Windows 9.0.23
- Microsoft Microsoft Visual Studio 2022 version 17.14 17.14.45
- Microsoft Microsoft Visual Studio 2026 version 18.11 18.11.4
- github.com/dotnet/aspnetcore@1fa5639 commit
- github.com/dotnet/aspnetcore@7ce5a6b commit
- github.com/dotnet/aspnetcore/releases/tag/v10.0.15 release
- github.com/dotnet/aspnetcore/releases/tag/v11.0.0 release
- github.com/dotnet/aspnetcore/releases/tag/v8.0.34 release
- github.com/dotnet/aspnetcore/releases/tag/v9.0.23 release
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109476 advisory
Is CVE-2026-109476 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerVendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-109476 updated cvss 6.1
dotnet8.0: dotnet11.0: dotnet9.0: dotnet10.0: ASP.NET Core Information Disclosure Vulnerability
-
Red Hat Enterprise Linux 8 dotnet, dotnet11.0, dotnet-host, dotnet-sdk-11.0, dotnet-hostfxr-11.0, dotnet-runtime-11.0, +10 more Red Hat Enterprise Linux 9 dotnet11.0, dotnet-host, dotnet-sdk-11.0, dotnet-hostfxr-11.0, dotnet-runtime-11.0, dotnet-sdk-aot-11.0, +9 more Red Hat Enterprise Linux 10 dotnet11.0affected: no fix available
-
Red Hat Enterprise Linux AppStream (v. 8) dotnet8.0 8.0.134-1.el8_10, dotnet9.0 9.0.124-1.el8_10, dotnet10.0 10.0.115-1.el8_10, dotnet-sdk-8.0 8.0.134-1.el8_10, dotnet-sdk-9.0 9.0.124-1.el8_10, dotnet-sdk-10.0 10.0.115-1.el8_10, +33 morefixed: vendor fix RHSA-2026:99053
-
Red Hat Enterprise Linux AppStream (v. 9) dotnet8.0 8.0.134-1.el9_9, dotnet9.0 9.0.124-1.el9_9, dotnet10.0 10.0.115-1.el9_9, dotnet-sdk-8.0 8.0.134-1.el9_9, dotnet-sdk-9.0 9.0.124-1.el9_9, dotnet-sdk-10.0 10.0.115-1.el9_9, +33 morefixed: vendor fix RHSA-2026:99142
-
Red Hat Enterprise Linux AppStream (v. 10) dotnet8.0 8.0.134-1.el10_3, dotnet9.0 9.0.124-1.el10_3, dotnet10.0 10.0.115-1.el10_3, dotnet-sdk-8.0 8.0.134-1.el10_3, dotnet-sdk-9.0 9.0.124-1.el10_3, dotnet-sdk-10.0 10.0.115-1.el10_3, +33 morefixed: vendor fix RHSA-2026:99143
-
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-8.0-source-built-artifacts 8.0.134-1.el9_9, dotnet-sdk-9.0-source-built-artifacts 9.0.124-1.el9_9, dotnet-sdk-10.0-source-built-artifacts 10.0.115-1.el9_9fixed: vendor fix RHSA-2026:99142
-
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-8.0-source-built-artifacts 8.0.134-1.el10_3, dotnet-sdk-9.0-source-built-artifacts 9.0.124-1.el10_3, dotnet-sdk-10.0-source-built-artifacts 10.0.115-1.el10_3fixed: vendor fix RHSA-2026:99143
-
Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-8.0-source-built-artifacts 8.0.134-1.el8_10, dotnet-sdk-9.0-source-built-artifacts 9.0.124-1.el8_10, dotnet-sdk-10.0-source-built-artifacts 10.0.115-1.el8_10fixed: vendor fix RHSA-2026:99053
-
Red Hat Hardened Images dotnet10.0 10.0.113-1.hum1, dotnet8.0 8.0.133-0.1.hum1, dotnet9.0 9.0.122-0.1.hum1not affected: component not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- yesterday
Exploit prediction
0.64% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C |
| GitHub | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N |
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | Microsoft.AspNetCore.App.Runtime.linux-arm | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.linux-arm64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.linux-musl-arm | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.linux-x64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.osx-arm64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.osx-x64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.win-arm64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.win-x64 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
| nuget | Microsoft.AspNetCore.App.Runtime.win-x86 | >=8.0.0-rc.1.23421.29, <8.0.34 >=9.0.0-preview.1.24081.5, <9.0.23 >=10.0.0-preview.1.25120.3, <10.0.15 >=11.0.0-preview.1.26104.118, <11.0.0 |
8.0.34 9.0.23 10.0.15 11.0.0 |
Affected products
- Microsoft .NET 10.0 installed on Linux
- Microsoft .NET 10.0 installed on Mac OS
- Microsoft .NET 10.0 installed on Windows
- Microsoft .NET 11.0 installed on Linux
- Microsoft .NET 11.0 installed on Mac OS
- Microsoft .NET 11.0 installed on Windows
- Microsoft .NET 8.0 installed on Linux
- Microsoft .NET 8.0 installed on Mac OS
- Microsoft .NET 8.0 installed on Windows
- Microsoft .NET 9.0 installed on Linux
- Microsoft .NET 9.0 installed on Mac OS
- Microsoft .NET 9.0 installed on Windows
- Microsoft Microsoft Visual Studio 2022 version 17.14
- Microsoft Microsoft Visual Studio 2026 version 18.11
- Microsoft Microsoft Visual Studio 2026 version 18.12
Classification
- Weakness
-
- CWE-116 Improper Encoding or Escaping of Output
References
-
msrc.microsoft.com
/update-guide/vulnerability/CVE-2026-109476
vendor-advisory, patch, web
-
github.com
/dotnet/aspnetcore/commit/1fa5639647ddd2061bafe2ccf60bdc1c345b0b34
web
-
github.com
/dotnet/aspnetcore/commit/7ce5a6b05d4d6694bb688bf7053ebb594c00a8e5
web
-
github.com
/dotnet/aspnetcore/security/advisories/GHSA-xhj5-c3g8-pfj8
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-109476
advisory
-
github.com
/dotnet/announcements/issues/508
web
-
github.com
/dotnet/aspnetcore
package
-
github.com
/dotnet/aspnetcore/discussions/70471
web
-
github.com
/dotnet/aspnetcore/releases/tag/v10.0.15
web
-
github.com
/dotnet/aspnetcore/releases/tag/v11.0.0
web
-
github.com
/dotnet/aspnetcore/releases/tag/v8.0.34
web
-
github.com
/dotnet/aspnetcore/releases/tag/v9.0.23
web
-
github.com
/dotnet/core/blob/main/release-notes/10.0/10.0.15/10.0.15.md
web
-
github.com
/dotnet/core/blob/main/release-notes/11.0/11.0.0/11.0.0.md
web
-
github.com
/dotnet/core/blob/main/release-notes/8.0/8.0.34/8.0.34.md
web
-
github.com
/dotnet/core/blob/main/release-notes/9.0/9.0.23/9.0.23.md
web
Sources
- CVE List CVE-2026-109476
- GitHub Advisory GHSA-xhj5-c3g8-pfj8
- NVD CVE-2026-109476
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.