Microsoft.AspNetCore.App.Runtime.linux arm: Microsoft Security Advisory CVE-2026-109478 - ASP.NET Core Denial of
Affects Microsoft.AspNetCore.App.Runtime.linux-armSource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 8.0.34 soon.
Data as of 11 Nov 2026, 01:50 UTC
Thin evidence
One scorer or none| CNA (microsoft) | CVSS 3.1 | 7.5 |
|---|
- Patch
- Available – fixed in 8.0.34, 9.0.0-preview.4.24267.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm and Microsoft.AspNetCore.App.Runtime.linux-arm64 and Microsoft.AspNetCore.App.Runtime.linux-musl-arm and Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 and Microsoft.AspNetCore.App.Runtime.linux-musl-x64 and Microsoft.AspNetCore.App.Runtime.linux-x64 and Microsoft.AspNetCore.App.Runtime.osx-arm64 and Microsoft.AspNetCore.App.Runtime.osx-x64 and Microsoft.AspNetCore.App.Runtime.win-arm64 and Microsoft.AspNetCore.App.Runtime.win-x64 and Microsoft.AspNetCore.App.Runtime.win-x86 to 8.0.34; Microsoft.AspNetCore.App.Runtime.linux-arm and Microsoft.AspNetCore.App.Runtime.linux-arm64 and Microsoft.AspNetCore.App.Runtime.linux-musl-arm and Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 and Microsoft.AspNetCore.App.Runtime.linux-musl-x64 and Microsoft.AspNetCore.App.Runtime.linux-x64 and Microsoft.AspNetCore.App.Runtime.osx-arm64 and Microsoft.AspNetCore.App.Runtime.osx-x64 and Microsoft.AspNetCore.App.Runtime.win-arm64 and Microsoft.AspNetCore.App.Runtime.win-x64 and Microsoft.AspNetCore.App.Runtime.win-x86 to 9.0.0-preview.4.24267.6.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| NuGetMicrosoft.AspNetCore.App.Runtime.linux-arm | Affected
| Fixed in
|
| NuGetMicrosoft.AspNetCore.App.Runtime.linux-arm64 | Affected
| Fixed in
|
| NuGetMicrosoft.AspNetCore.App.Runtime.linux-musl-arm | Affected
| Fixed in
|
| NuGetMicrosoft.AspNetCore.App.Runtime.linux-musl-arm64 | Affected
| Fixed in
|
| NuGetMicrosoft.AspNetCore.App.Runtime.linux-musl-x64 | Affected
| Fixed in
|
| NuGetMicrosoft.AspNetCore.App.Runtime.linux-x64 | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Apply the official patches provided by Microsoft. Upgrade affected Microsoft.AspNetCore.App.Runtime packages to version 8.0.34 or later for .NET 8.0, and to 9.0.0-preview.4.24267.6 or later for .NET 9.0 previews. No other mitigation or workaround is indicated by the vendor advisory.
Description
A vulnerability in ASP.NET Core allows processing of comma-separated HTTP header values to cause excessive memory allocations leading to resource exhaustion. This denial of service issue affects multiple platforms and architectures. The flaw is tracked as CVE-2026-109478 with a CVSS 3.1 base score of 7.5 (high severity). Fixed versions have been released for affected runtime packages in .NET 8.0 and 9.0.
References
- github.com/dotnet/aspnetcore/security/advisories/GHSA-r3qf-p3jm-8h4p (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-109478 (opens in a new tab)
- github.com/dotnet/announcements/issues/515 (opens in a new tab)
- github.com/dotnet/aspnetcore/commit/2523887d4cca7013afa2737e20cb7f6ba1eed8ff (opens in a new tab)
- github.com/dotnet/aspnetcore/commit/effb34d85fdc5137ee4bd87d52560433c3df02e7 (opens in a new tab)
- github.com/dotnet/aspnetcore (opens in a new tab)
- github.com/dotnet/aspnetcore/discussions/70479 (opens in a new tab)
- github.com/dotnet/aspnetcore/releases/tag/v8.0.34 (opens in a new tab)
- github.com/dotnet/aspnetcore/releases/tag/v9.0.0-preview.4.24267.6 (opens in a new tab)
- github.com/dotnet/core/blob/main/release-notes/8.0/8.0.34/8.0.34.md (opens in a new tab)
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109478 (opens in a new tab)