How severe is CVE-2026-26130?

CVE-2026-26130 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-26130?

CVE-2026-26130 affects the following packages: Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet), Microsoft.AspNetCore.App.Runtime.linux-musl-arm (NuGet), and 28 more. Ecosystems affected: NuGet.

How do I fix CVE-2026-26130?

Update Microsoft.AspNetCore.App.Runtime.linux-arm to 8.0.25 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-26130 is resolved across your whole dependency graph.

How do I detect CVE-2026-26130 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.App.Runtime.linux-arm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-26130 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-26130?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-26130 can be triaged on real exposure rather than presence alone.

Is CVE-2026-26130 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-26130 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-26130?

CVE-2026-26130 has an EPSS (Exploit Prediction Scoring System) score of 2.8%, placing it in the 86th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-26130?

CVE-2026-26130 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-26130 published, and has it been updated?

CVE-2026-26130 was published on March 10, 2026 and was last updated on July 22, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

Not in CISA KEV

HIGH severity

CVE-2026-26130 — Microsoft.AspNetCore.App.…

HIGH

CVE-2026-26130 is a high-severity (CVSS 7.5) CWE-770 vulnerability in Microsoft.AspNetCore.App.Runtime.linux-arm. A fix is available for Microsoft.AspNetCore.App.Runtime.linux-arm — see the affected versions and patch details below.

.NET Denial of Service Vulnerability

Also known asBIT-aspnet-core-2026-26130GHSA-4vgm-c2wm-63mw

Published

Mar 10, 2026

Updated

Jul 22, 2026

Affected

36 pkgs

Patched

36 / 36

Exploits

None indexed

Exploitation data as of Sep 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-26130.

EPSS Exploitation Probability

via FIRST.org ↗

2.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs86th percentile — riskier than 86% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2026-26130 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

36 pkgs affected

.NETMicrosoft.AspNetCore.App.Runtime.linux-arm.NETMicrosoft.AspNetCore.App.Runtime.linux-arm.NETMicrosoft.AspNetCore.App.Runtime.linux-arm.NETMicrosoft.AspNetCore.App.Runtime.linux-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-musl-arm.NETMicrosoft.AspNetCore.App.Runtime.linux-musl-arm+28 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

Microsoft Security Advisory CVE-2026-26130 – .NET Denial of Service Vulnerability

Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0, .NET 9.0, and .NET 10.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A denial of service vulnerability exists in ASP.NET Core due to uncontrolled resource consumption. A specially crafted message to a SignalR server can exhaust an internal buffer and cause a Denial of Service.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/385

CVSS Details

Version: 3.1
Score: 7.5
Vector: 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
Severity: High
Weakness: CWE-770 (Uncontrolled Resource Consumption)

Affected Platforms

Platforms: All
Architectures: All

Affected Products

<a name=".NET 8"></a>.NET 8

Package name	Affected version	Patched version
Microsoft.AspNetCore.App.Runtime.linux-arm	>= 8.0.0, < =8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.linux-arm64	>= 8.0.0, < =8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.linux-musl-arm	>= 8.0.0, <= 8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64	>= 8.0.0, <= 8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.linux-musl-x64	>= 8.0.0, < =8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.linux-x64	>= 8.0.0, < =8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.osx-arm64	>= 8.0.0, < =8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.osx-x64	>= 8.0.0, <= 8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.win-arm	>= 8.0.0, <= 8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.win-arm64	>= 8.0.0, <= 8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.win-x64	>= 8.0.0, < =8.0.24	8.0.25
Microsoft.AspNetCore.App.Runtime.win-x86	>= 8.0.0, <= 8.0.24	8.0.25

<a name=".NET 9"></a>.NET 9

Package name	Affected version	Patched version
Microsoft.AspNetCore.App.Runtime.linux-arm	>= 9.0.0, < =9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.linux-arm64	>= 9.0.0, < =9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.linux-musl-arm	>= 9.0.0, <= 9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64	>= 9.0.0, <= 9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.linux-musl-x64	>= 9.0.0, < =9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.linux-x64	>= 9.0.0, < =9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.osx-arm64	>= 9.0.0, < =9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.osx-x64	>= 9.0.0, < =9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.win-arm	>= 9.0.0, <= 9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.win-arm64	>= 9.0.0, < =9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.win-x64	>= 9.0.0, <= 9.0.13	9.0.14
Microsoft.AspNetCore.App.Runtime.win-x86	>= 9.0.0, <= 9.0.13	9.0.14

<a name=".NET 10"></a>.NET 10

Package name	Affected version	Patched version
Microsoft.AspNetCore.App.Runtime.linux-arm	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.linux-arm64	>= 10.0.0, <= 10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.linux-musl-arm	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.linux-musl-x64	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.linux-x64	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.osx-arm64	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.osx-x64	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.win-arm	>= 10.0.0, < =10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.win-arm64	>= 10.0.0, <= 10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.win-x64	>= 10.0.0, <= 10.0.3	10.0.4
Microsoft.AspNetCore.App.Runtime.win-x86	>= 10.0.0, <= 10.0.3	10.0.4

Advisory FAQ

<a name="how-affected"></a>How do I know if I am affected?

If using an affected package listed in affected products or affected packages, you're exposed to the vulnerability.

<a name="how-fix"></a>How do I fix the issue?

To fix the issue please install the latest version of .NET 8.0, NET 9.0, or .NET 10.0, as appropriate. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs.
If your application references the vulnerable package, update the package reference to the patched version. You can list the versions you have installed by running the dotnet --info command.

Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.

Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

Other Information

Reporting Security Issues

If you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ.

Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.

Support

You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.

Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

External Links

CVE-2026-26130

Acknowledgements

Bartłomiej Dach

Revisions

V1.0 (March 10, 2026): Advisory published.

Affected Packages

36 total 36 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-arm`	≥ 8.0.0&&< 8.0.25	8.0.25`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 8.0.25`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-arm`	≥ 9.0.0&&< 9.0.14	9.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 9.0.14`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-arm`	≥ 10.0.0&&< 10.0.4	10.0.4`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 10.0.4`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-arm64`	≥ 8.0.0&&< 8.0.25	8.0.25`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 8.0.25`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-arm64`	≥ 9.0.0&&< 9.0.14	9.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 9.0.14`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-arm64`	≥ 10.0.0&&< 10.0.4	10.0.4`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 10.0.4`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.App.Runtime.linux-arm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.AspNetCore.App.Runtime.linux-arm to 8.0.25 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-26130 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-26130 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-26130. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

Product	Fixed in	Advisory
Red Hat Enterprise Linux 10	`dotnet9.0-0:9.0.115-1.el10_1`	RHSA-2026:4450
Red Hat Enterprise Linux 10	`dotnet8.0-0:8.0.125-1.el10_1`	RHSA-2026:4451
Red Hat Enterprise Linux 10	`dotnet10.0-0:10.0.104-1.el10_1`	RHSA-2026:4453
Red Hat Enterprise Linux 10.0 Extended Update Support	`dotnet9.0-0:9.0.115-1.el10_0`	RHSA-2026:10083
Red Hat Enterprise Linux 10.0 Extended Update Support	`dotnet8.0-0:8.0.125-1.el10_0`	RHSA-2026:10091
Red Hat Enterprise Linux 8	`dotnet9.0-0:9.0.115-1.el8_10`	RHSA-2026:4443
Red Hat Enterprise Linux 8	`dotnet8.0-0:8.0.125-1.el8_10`	RHSA-2026:4455
Red Hat Enterprise Linux 8	`dotnet10.0-0:10.0.104-1.el8_10`	RHSA-2026:4458

UbuntuHIGH

USN-8085-1Ubuntu

Frequently Asked Questions

# Microsoft Security Advisory CVE-2026-26130 – .NET Denial of Service Vulnerability ## Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0, .NET 9.0, and .NET 10.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in ASP.NET Core due to uncontrolled resource consumption. A specially crafted message to a SignalR server can exhaust an internal buffer and cause a Denial of Service. ## Announcement Announcement f

O3 Security · Impact-Aware SCA

Is CVE-2026-26130 in your dependencies?

O3 Security finds CVE-2026-26130 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works