How severe is CVE-2022-21986?

CVE-2022-21986 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2022-21986?

CVE-2022-21986 affects the following packages: Microsoft.AspNetCore.App.Runtime.win-x64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet), Microsoft.AspNetCore.App.Runtime.win-x86 (NuGet), Microsoft.AspNetCore.App.Runtime.osx-x64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet), Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet), Microsoft.AspNetCore.App.Runtime.win-arm64 (NuGet), and 15 more. Ecosystems affected: NuGet.

How do I fix CVE-2022-21986?

Update Microsoft.AspNetCore.App.Runtime.win-x64 to 5.0.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-21986 is resolved across your whole dependency graph.

How do I detect CVE-2022-21986 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.App.Runtime.win-x64, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2022-21986 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2022-21986 actively exploited in the wild?

No public exploit code has been indexed for CVE-2022-21986 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-2022-21986?

CVE-2022-21986 has an EPSS (Exploit Prediction Scoring System) score of 3.7%, placing it in the 90th 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.

When was CVE-2022-21986 published, and has it been updated?

CVE-2022-21986 was published on February 9, 2022 and was last updated on October 24, 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-2022-21986 — Microsoft.AspNetCore.App.…

HIGH

CVE-2022-21986 is a high-severity (CVSS 7.5) vulnerability in Microsoft.AspNetCore.App.Runtime.win-x64. A fix is available for Microsoft.AspNetCore.App.Runtime.win-x64 — see the affected versions and patch details below.

.NET Denial of Service Vulnerability

Also known asBIT-dotnet-2022-21986BIT-dotnet-sdk-2022-21986GHSA-x459-p2rx-f8ff

Published

Feb 9, 2022

Updated

Oct 24, 2026

Affected

23 pkgs

Patched

23 / 23

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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-2022-21986.

EPSS Exploitation Probability

via FIRST.org ↗

3.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs90th percentile — riskier than 90% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

23 pkgs affected

.NETMicrosoft.AspNetCore.App.Runtime.win-x64.NETMicrosoft.AspNetCore.App.Runtime.linux-x64.NETMicrosoft.AspNetCore.App.Runtime.win-x86.NETMicrosoft.AspNetCore.App.Runtime.osx-x64.NETMicrosoft.AspNetCore.App.Runtime.linux-musl-x64.NETMicrosoft.AspNetCore.App.Runtime.linux-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-arm.NETMicrosoft.AspNetCore.App.Runtime.win-arm64+15 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

A Denial of Service vulnerability exists in .NET 6.0 and .NET 5.0 when the Kestrel web server processes certain HTTP/2 and HTTP/3 requests.

Affected Software

Any .NET 6.0 application running on .NET 6.0.1 or lower.
Any .NET 5.0 application running on .NET 5.0.13 or lower.

Patches

To fix the issue, please install the latest version of .NET 6.0 or .NET 5.0. 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 you're using .NET Core 6.0, you should download and install Runtime 6.0.2 or SDK 6.0.102 (for Visual Studio 2022 v17.1) from https://dotnet.microsoft.com/download/dotnet-core/6.0.
If you're using .NET 5.0, you should download and install Runtime 5.0.14 or SDK 5.0.114 (for Visual Studio 2019 v16.8) or SDK 5.0.405 (for Visual Studio 2011 v16.11) from https://dotnet.microsoft.com/download/dotnet-core/5.0.

.NET 6.0 and .NET 5.0 updates are also available from Microsoft Update. To access this either type "Check for updates" in your Windows search, or open Settings, choose Update & Security and then click Check for Updates.

Other Details

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/207
An Issue for this can be found at https://github.com/dotnet/aspnetcore/issues/40072
MSRC details for this can be found at https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2022-21986

Affected Packages

23 total 23 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.win-x64`	≥ 5.0.0&&< 5.0.14	5.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.win-x64 --version 5.0.14`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-x64`	≥ 5.0.0&&< 5.0.14	5.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-x64 --version 5.0.14`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.win-x86`	≥ 5.0.0&&< 5.0.14	5.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.win-x86 --version 5.0.14`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.osx-x64`	≥ 5.0.0&&< 5.0.14	5.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.osx-x64 --version 5.0.14`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-musl-x64`	≥ 5.0.0&&< 5.0.14	5.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-musl-x64 --version 5.0.14`
.NETNuGet	`Microsoft.AspNetCore.App.Runtime.linux-arm64`	≥ 5.0.0&&< 5.0.14	5.0.14`dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm64 --version 5.0.14`

Affected Products

4 products · 7 configurations

fedorafedoraproject

2 versions

3435

Application

.netmicrosoft

≥ 6.0.0 && < 6.0.2

range

Application

visual studio 2019microsoft

≥ 16.0 && ≤ 16.11

range

Application

visual studio 2022microsoft

≥ 17.0 && < 17.0.6

range

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.win-x64, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.AspNetCore.App.Runtime.win-x64 to 5.0.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-21986 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

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
.NET Core on Red Hat Enterprise Linux	`rh-dotnet50-dotnet-0:5.0.211-1.el7_9`	RHSA-2022:0499
.NET Core on Red Hat Enterprise Linux	`rh-dotnet60-dotnet-0:6.0.102-1.el7_9`	RHSA-2022:0500
Red Hat Enterprise Linux 8	`dotnet5.0-0:5.0.211-1.el8_5`	RHSA-2022:0495
Red Hat Enterprise Linux 8	`dotnet6.0-0:6.0.102-1.el8_5`	RHSA-2022:0496

Frequently Asked Questions

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 6.0 and .NET 5.0. 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 .NET 6.0 and .NET 5.0 when the Kestrel web server processes certain HTTP/2 and HTTP/3 requests. ### Affected Software * Any .NET 6.0 application running on .NET 6.0.1 or lower. * Any .NET 5.0 application running on .NET 5.0.13 or lower. ### Patches To fix the issue, please install the latest version of .NET 6.0

O3 Security · Impact-Aware SCA

Is CVE-2022-21986 in your dependencies?

Find it across NuGet, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

7.5/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

aspnetcore

6.3/10

Code-Review5/10

Maintained10/10

Branch-Protection8/10

Assessed Oct 19, 2026

Timeline

Disclosed

Feb 9, 2022

Last updated

Oct 24, 2026

Identifiers

CVE-2022-21986

GHSA-x459-p2rx-f8ff

BIT-dotnet-2022-21986

BIT-dotnet-sdk-2022-21986

References

Advisorynvd.nist.gov · CVE 2022 21986 Webmsrc.microsoft.com · CVE 2022 21986 Webgithub.com · GHSA x459 p2rx f8ff Webgithub.com Weblists.fedoraproject.org · 4HMQOHV7G5TF6OMBN6DNTDOKQQU7KHMM Weblists.fedoraproject.org · CCTBSBE3PNIMXG6ALX2CQG4ZEH7W3YAT Webportal.msrc.microsoft.com · CVE 2022 21986 Packagegithub.com · aspnetcore

Related vulnerabilities

This CVE is high severity; 7 of 8 other CVEs affecting Microsoft.AspNetCore.App.Runtime.win-x64 are rated as high or higher (top: critical).

CVE-2026-70183CVE-2026-70196CVE-2026-96236CVE-2026-70188CVE-2026-70186CVE-2026-88092CVE-2026-70181CVE-2026-70175

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2022-21986 — Microsoft.AspNetCore.App.…

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Software

Patches

Other Details

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2022-21986 in your dependencies?