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Fencer Vulns
high 7.5

CVE-2026-26127 json

.NET Denial of Service Vulnerability

published 2026-03-10 8 mo ago modified 2026-09-10 1 mo ago also BIT-dotnet-2026-26127 , BIT-dotnet-sdk-2026-26127 , EUVD-2026-10691 , GHSA-73j8-2gch-69rq

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.3%
EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits
0
none known

Summary

Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.

Patch / fix

  • nuget Microsoft.Bcl.Memory 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.linux-arm 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.linux-arm64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.linux-musl-arm 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.linux-musl-arm64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.linux-musl-x64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.linux-x64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.osx-arm64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.osx-x64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.win-arm 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.win-arm64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.win-x64 9.0.14, 10.0.4
  • nuget Microsoft.NetCore.App.Runtime.win-x86 9.0.14, 10.0.4
  • bitnami dotnet 9.0.14, 10.0.4
  • bitnami dotnet-sdk 9.0.14, 10.0.4
  • Microsoft .NET 10.0 10.0.4
  • Microsoft .NET 9.0 9.0.14
  • Microsoft Microsoft.Bcl.Memory 9.0.14, 10.0.4
  • dotnet9 Ubuntu 25.10 9.0.115-9.0.14-0ubuntu1~25.10.1
  • dotnet10 Ubuntu 24.04 LTS 10.0.104-10.0.4-0ubuntu1~24.04.1
  • dotnet10 Ubuntu 25.10 10.0.104-10.0.4-0ubuntu1~25.10.1

ubuntu advisories UBUNTU-CVE-2026-26127

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

  • dotnet RHEL 8 10.0.104-1.el8_10
  • dotnet10.0 RHEL 8 10.0.104-1.el8_10
  • dotnet-host RHEL 8 10.0.4-1.el8_10
  • dotnet-sdk-10.0 RHEL 8 10.0.104-1.el8_10
  • dotnet-hostfxr-10.0 RHEL 8 10.0.4-1.el8_10
  • dotnet-runtime-10.0 RHEL 8 10.0.4-1.el8_10
  • dotnet-sdk-aot-10.0 RHEL 8 10.0.104-1.el8_10
  • dotnet-sdk-dbg-10.0 RHEL 8 10.0.104-1.el8_10

red hat advisories RHSA-2026:10083RHSA-2026:10085RHSA-2026:4458RHSA-2026:4456RHSA-2026:4453RHSA-2026:4450

  • dotnet-sdk-9.0 AlmaLinux 8 9.0.115-1.el8_10
  • dotnet-hostfxr-9.0 AlmaLinux 8 9.0.14-1.el8_10
  • dotnet-runtime-9.0 AlmaLinux 8 9.0.14-1.el8_10
  • dotnet-sdk-aot-9.0 AlmaLinux 8 9.0.115-1.el8_10
  • dotnet-sdk-dbg-9.0 AlmaLinux 8 9.0.115-1.el8_10
  • dotnet-templates-9.0 AlmaLinux 8 9.0.115-1.el8_10
  • aspnetcore-runtime-9.0 AlmaLinux 8 9.0.14-1.el8_10
  • dotnet-runtime-dbg-9.0 AlmaLinux 8 9.0.14-1.el8_10

almalinux advisories ALSA-2026:4443ALSA-2026:4445ALSA-2026:4450ALSA-2026:4453ALSA-2026:4456ALSA-2026:4458

  • dotnet9.0 Rocky Linux 10 9.0.115-1.el10_1
  • dotnet10.0 Rocky Linux 10 10.0.104-1.el10_1
  • dotnet10.0 Rocky Linux 9 10.0.104-1.el9_7
  • dotnet9.0 Rocky Linux 9 9.0.115-1.el9_7
  • dotnet9.0 Rocky Linux 8 9.0.115-1.el8_10
  • dotnet10.0 Rocky Linux 8 10.0.104-1.el8_10

rocky linux advisories RLSA-2026:4450RLSA-2026:4453RLSA-2026:4445RLSA-2026:4456RLSA-2026:4443RLSA-2026:4458

  • dotnet9-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 9.0.14-r0
  • dotnet10-runtime Alpine 3.24, Alpine 3.23 10.0.4-r0

alpine advisories ALPINE-CVE-2026-26127

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-2026-26127 updated cvss 7.5

.net: .NET: Denial of Service via out-of-bounds read

  • Red Hat CodeReady Linux Builder EUS (v.9.6) dotnet-sdk-9.0-source-built-artifacts 9.0.115-1.el9_6
    fixed: vendor fix RHSA-2026:10085
  • Red Hat Enterprise Linux AppStream (v. 8) dotnet 10.0.104-1.el8_10, dotnet9.0 9.0.115-1.el8_10, dotnet-host 10.0.4-1.el8_10, dotnet10.0 10.0.104-1.el8_10, dotnet-sdk-9.0 9.0.115-1.el8_10, dotnet-sdk-10.0 10.0.104-1.el8_10, +23 more
    fixed: vendor fix RHSA-2026:4458
  • Red Hat Enterprise Linux AppStream (v. 9) dotnet9.0 9.0.115-1.el9_7, dotnet-host 10.0.4-1.el9_7, dotnet10.0 10.0.104-1.el9_7, dotnet-sdk-9.0 9.0.115-1.el9_7, dotnet-sdk-10.0 10.0.104-1.el9_7, dotnet-hostfxr-9.0 9.0.14-1.el9_7, +22 more
    fixed: vendor fix RHSA-2026:4445
  • Red Hat Enterprise Linux AppStream (v. 10) dotnet9.0 9.0.115-1.el10_1, dotnet-host 10.0.4-1.el10_1, dotnet10.0 10.0.104-1.el10_1, dotnet-sdk-9.0 9.0.115-1.el10_1, dotnet-sdk-10.0 10.0.104-1.el10_1, dotnet-hostfxr-9.0 9.0.14-1.el10_1, +22 more
    fixed: vendor fix RHSA-2026:4453
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) dotnet9.0 9.0.115-1.el10_0, dotnet-host 9.0.14-1.el10_0, dotnet-sdk-9.0 9.0.115-1.el10_0, dotnet-hostfxr-9.0 9.0.14-1.el10_0, dotnet-runtime-9.0 9.0.14-1.el10_0, dotnet-sdk-aot-9.0 9.0.115-1.el10_0, +9 more
    fixed: vendor fix RHSA-2026:10083
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) dotnet9.0 9.0.115-1.el9_6, dotnet-host 9.0.14-1.el9_6, dotnet-sdk-9.0 9.0.115-1.el9_6, dotnet-hostfxr-9.0 9.0.14-1.el9_6, dotnet-runtime-9.0 9.0.14-1.el9_6, dotnet-sdk-aot-9.0 9.0.115-1.el9_6, +9 more
    fixed: vendor fix RHSA-2026:10085
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-9.0-source-built-artifacts 9.0.115-1.el9_7, dotnet-sdk-10.0-source-built-artifacts 10.0.104-1.el9_7
    fixed: vendor fix RHSA-2026:4445
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-9.0-source-built-artifacts 9.0.115-1.el10_1, dotnet-sdk-10.0-source-built-artifacts 10.0.104-1.el10_1
    fixed: vendor fix RHSA-2026:4453
show 4 more
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) dotnet-sdk-9.0-source-built-artifacts 9.0.115-1.el10_0
    fixed: vendor fix RHSA-2026:10083
  • Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-9.0-source-built-artifacts 9.0.115-1.el8_10, dotnet-sdk-10.0-source-built-artifacts 10.0.104-1.el8_10
    fixed: vendor fix RHSA-2026:4458
  • Red Hat Enterprise Linux 8 dotnet, dotnet8.0, dotnet-host, dotnet-sdk-8.0, dotnet-hostfxr-8.0, dotnet-runtime-8.0, +10 more Red Hat Enterprise Linux 9 dotnet6.0, dotnet7.0, dotnet8.0, dotnet-host, dotnet-sdk-6.0, dotnet-sdk-7.0, +29 more
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 10 dotnet8.0
    not 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
yes
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

2.27% chance of exploitation in the next 30 days, higher than 83% 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
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.Bcl.Memory
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.linux-arm
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.linux-arm64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.linux-musl-arm
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.linux-musl-arm64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.linux-musl-x64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.linux-x64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.osx-arm64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.osx-x64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.win-arm
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.win-arm64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.win-x64
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
nuget Microsoft.NetCore.App.Runtime.win-x86
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
bitnami dotnet
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4
bitnami dotnet-sdk
>=9.0.0, <9.0.14
>=10.0.0, <10.0.4
9.0.14
10.0.4

Affected products

  • Microsoft .NET 10.0
  • Microsoft .NET 9.0
  • Microsoft Microsoft.Bcl.Memory

Classification

Weakness

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.