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Fencer Vulns
high 7.5

CVE-2026-42899 json

ASP.NET Core Denial of Service Vulnerability

published 2026-05-12 5 mo ago modified 2026-10-26 13 d ago also BIT-dotnet-2026-42899 , BIT-dotnet-sdk-2026-42899 , EUVD-2026-29719 , GHSA-9v76-4qcc-frgh

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.4%
EPSS 2.4% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

Loop with unreachable exit condition ('infinite loop') in ASP.NET Core allows an unauthorized attacker to deny service over a network.

Patch / fix

  • nuget Microsoft.AspNetCore.App.Runtime.win-arm 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.win-arm64 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.win-x64 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.win-x86 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.linux-arm 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.linux-arm64 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.linux-musl-x64 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.linux-x64 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.osx-arm64 8.0.27, 9.0.16, 10.0.8
  • nuget Microsoft.AspNetCore.App.Runtime.osx-x64 8.0.27, 9.0.16, 10.0.8
  • bitnami dotnet 8.0.27, 9.0.16, 10.0.8
  • bitnami dotnet-sdk 8.0.27, 9.0.16, 10.0.8
  • Microsoft .NET 10.0 10.0.8
  • Microsoft .NET 8.0 8.0.27
  • Microsoft .NET 9.0 9.0.16
  • Red Hat Red Hat Enterprise Linux 10 0:8.0.127-1.el10_2, 0:9.0.117-1.el10_2, 0:10.0.108-1.el10_2
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:8.0.127-1.el10_0, 0:9.0.117-1.el10_0
  • Red Hat Red Hat Enterprise Linux 8 0:8.0.127-1.el8_10, 0:9.0.117-1.el8_10, 0:10.0.108-1.el8_10
  • Red Hat Red Hat Enterprise Linux 9 0:8.0.127-1.el9_8, 0:9.0.117-1.el9_8, 0:10.0.108-1.el9_8
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:8.0.127-1.el9_4
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:8.0.127-1.el9_6, 0:9.0.117-1.el9_6
  • Red Hat Red Hat Hardened Images 8.0.127-1.hum1, 9.0.117-1.hum1, 10.0.108-1.hum1
  • dotnet8 Ubuntu 22.04 LTS 8.0.127-8.0.27-0ubuntu1~22.04.1
  • dotnet8 Ubuntu 24.04 LTS 8.0.127-8.0.27-0ubuntu1~24.04.1
  • dotnet8 Ubuntu 25.10 8.0.127-8.0.27-0ubuntu1~25.10.1
  • dotnet9 Ubuntu 25.10 9.0.117-9.0.16-0ubuntu1~25.10.1
  • dotnet10 Ubuntu 24.04 LTS 10.0.108-10.0.8-0ubuntu1~24.04.1
  • dotnet10 Ubuntu 25.10 10.0.108-10.0.8-0ubuntu1~25.10.1
  • dotnet10 Ubuntu 26.10 10.0.108-10.0.8-0ubuntu1
  • dotnet10 Ubuntu 26.04 LTS 10.0.108-10.0.8-0ubuntu1~26.04.1

ubuntu advisories UBUNTU-CVE-2026-42899

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • dotnet10.0 RHEL 10.2 10.0.108-1.el10_2
  • dotnet-host RHEL 10.2 10.0.8-1.el10_2
  • dotnet-sdk-10.0 RHEL 10.2 10.0.108-1.el10_2
  • dotnet-hostfxr-10.0 RHEL 10.2 10.0.8-1.el10_2
  • dotnet-runtime-10.0 RHEL 10.2 10.0.8-1.el10_2
  • dotnet-sdk-aot-10.0 RHEL 10.2 10.0.108-1.el10_2
  • dotnet-sdk-dbg-10.0 RHEL 10.2 10.0.108-1.el10_2
  • dotnet-templates-10.0 RHEL 10.2 10.0.108-1.el10_2

red hat advisories RHSA-2026:24336RHSA-2026:24335RHSA-2026:24333RHSA-2026:24334RHSA-2026:24332RHSA-2026:22145

  • dotnet-host AlmaLinux 10 10.0.8-1.el10_2
  • dotnet-sdk-10.0 AlmaLinux 10 10.0.108-1.el10_2
  • dotnet-hostfxr-10.0 AlmaLinux 10 10.0.8-1.el10_2
  • dotnet-runtime-10.0 AlmaLinux 10 10.0.8-1.el10_2
  • dotnet-sdk-aot-10.0 AlmaLinux 10 10.0.108-1.el10_2
  • dotnet-sdk-dbg-10.0 AlmaLinux 10 10.0.108-1.el10_2
  • dotnet-templates-10.0 AlmaLinux 10 10.0.108-1.el10_2
  • aspnetcore-runtime-10.0 AlmaLinux 10 10.0.8-1.el10_2

almalinux advisories ALSA-2026:22145ALSA-2026:21754ALSA-2026:21286ALSA-2026:21291ALSA-2026:21293ALSA-2026:21294

  • dotnet10.0 Rocky Linux 10 10.0.108-1.el10_2
  • dotnet8.0 Rocky Linux 10 8.0.127-1.el10_2
  • dotnet9.0 Rocky Linux 10 9.0.117-1.el10_2
  • dotnet8.0 Rocky Linux 9 8.0.127-1.el9_8
  • dotnet9.0 Rocky Linux 9 9.0.117-1.el9_8
  • dotnet10.0 Rocky Linux 9 10.0.108-1.el9_8
  • dotnet8.0 Rocky Linux 8 8.0.127-1.el8_10
  • dotnet9.0 Rocky Linux 8 9.0.117-1.el8_10

rocky linux advisories RLSA-2026:22145RLSA-2026:21286RLSA-2026:21754RLSA-2026:21293RLSA-2026:21296RLSA-2026:21297

  • dotnet8-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 8.0.27-r0
  • dotnet9-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 9.0.16-r0
  • dotnet10-runtime Alpine 3.24, Alpine 3.23 10.0.8-r0

alpine advisories ALPINE-CVE-2026-42899

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-42899 updated cvss 7.5

dotnet: .NET: infinite loop allows an attacker to cause a denial of service

  • Red Hat CodeReady Linux Builder EUS (v.9.6) dotnet-sdk-8.0-source-built-artifacts 8.0.127-1.el9_6, dotnet-sdk-9.0-source-built-artifacts 9.0.117-1.el9_6
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:24335
  • Red Hat Enterprise Linux AppStream (v. 8) dotnet 10.0.108-1.el8_10, dotnet8.0 8.0.127-1.el8_10, dotnet9.0 9.0.117-1.el8_10, dotnet-host 10.0.8-1.el8_10, dotnet10.0 10.0.108-1.el8_10, dotnet-sdk-8.0 8.0.127-1.el8_10, +35 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:21295
  • Red Hat Enterprise Linux AppStream (v. 9) dotnet8.0 8.0.127-1.el9_8, dotnet9.0 9.0.117-1.el9_8, dotnet-host 10.0.8-1.el9_8, dotnet10.0 10.0.108-1.el9_8, dotnet-sdk-8.0 8.0.127-1.el9_8, dotnet-sdk-9.0 9.0.117-1.el9_8, +34 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:21297
  • Red Hat Enterprise Linux AppStream (v. 10) dotnet8.0 8.0.127-1.el10_2, dotnet9.0 9.0.117-1.el10_2, dotnet-host 10.0.8-1.el10_2, dotnet10.0 10.0.108-1.el10_2, dotnet-sdk-8.0 8.0.127-1.el10_2, dotnet-sdk-9.0 9.0.117-1.el10_2, +34 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:22145
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) dotnet8.0 8.0.127-1.el9_4, dotnet-host 8.0.27-1.el9_4, dotnet-sdk-8.0 8.0.127-1.el9_4, dotnet-hostfxr-8.0 8.0.27-1.el9_4, dotnet-runtime-8.0 8.0.27-1.el9_4, dotnet-sdk-dbg-8.0 8.0.127-1.el9_4, +8 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:24334
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) dotnet8.0 8.0.127-1.el10_0, dotnet9.0 9.0.117-1.el10_0, dotnet-host 9.0.16-1.el10_0, dotnet-sdk-8.0 8.0.127-1.el10_0, dotnet-sdk-9.0 9.0.117-1.el10_0, dotnet-hostfxr-8.0 8.0.27-1.el10_0, +21 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:24332
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) dotnet8.0 8.0.127-1.el9_6, dotnet9.0 9.0.117-1.el9_6, dotnet-host 9.0.16-1.el9_6, dotnet-sdk-8.0 8.0.127-1.el9_6, dotnet-sdk-9.0 9.0.117-1.el9_6, dotnet-hostfxr-8.0 8.0.27-1.el9_6, +21 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:24335
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-8.0-source-built-artifacts 8.0.127-1.el9_8, dotnet-sdk-9.0-source-built-artifacts 9.0.117-1.el9_8, dotnet-sdk-10.0-source-built-artifacts 10.0.108-1.el9_8
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:21297
show 5 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-8.0-source-built-artifacts 8.0.127-1.el10_2, dotnet-sdk-9.0-source-built-artifacts 9.0.117-1.el10_2, dotnet-sdk-10.0-source-built-artifacts 10.0.108-1.el10_2
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:22145
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) dotnet-sdk-8.0-source-built-artifacts 8.0.127-1.el10_0, dotnet-sdk-9.0-source-built-artifacts 9.0.117-1.el10_0
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:24332
  • Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-8.0-source-built-artifacts 8.0.127-1.el8_10, dotnet-sdk-9.0-source-built-artifacts 9.0.117-1.el8_10, dotnet-sdk-10.0-source-built-artifacts 10.0.108-1.el8_10
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:21295
  • Red Hat Hardened Images dotnet8.0 8.0.127-1.hum1, dotnet9.0 9.0.117-1.hum1, dotnet10.0 10.0.108-1.hum1
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:17464
  • Red Hat Hardened Images dotnet-host 10.0.8-1.hum1, dotnet-sdk-8.0 8.0.127-1.hum1, dotnet-sdk-9.0 9.0.117-1.hum1, dotnet-sdk-10.0 10.0.108-1.hum1, dotnet-hostfxr-8.0 8.0.27-1.hum1, dotnet-hostfxr-9.0 9.0.16-1.hum1, +34 more
    not affected: vulnerable code 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
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

2.43% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
nuget Microsoft.AspNetCore.App.Runtime.win-arm
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.win-arm64
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.win-x64
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.win-x86
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.linux-arm
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.linux-arm64
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.linux-musl-arm64
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.linux-musl-x64
>=8.0.0, <8.0.27
>=10.0.0, <10.0.8
>=9.0.0, <9.0.16
8.0.27
10.0.8
9.0.16
nuget Microsoft.AspNetCore.App.Runtime.linux-x64
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.osx-arm64
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
nuget Microsoft.AspNetCore.App.Runtime.osx-x64
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
bitnami dotnet
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8
bitnami dotnet-sdk
>=8.0.0, <8.0.27
>=9.0.0, <9.0.16
>=10.0.0, <10.0.8
8.0.27
9.0.16
10.0.8

Affected products

  • Microsoft .NET 10.0
  • Microsoft .NET 8.0
  • Microsoft .NET 9.0
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat Hardened Images

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Vulns 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.