Microsoft Security Advisory CVE-2026-32203 – .NET and Visual Studio Denial of Service VulnerabilityGHSA-6588-8gv4-xfgh
HIGHGHSA-6588-8gv4-xfgh is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in System.Security.Cryptography.Xml. A fix is available for System.Security.Cryptography.Xml — see the affected versions and patch details below.
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 GHSA-6588-8gv4-xfgh.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-6588-8gv4-xfgh by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 396,966 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
System.Security.Cryptography.Xml.NETSystem.Security.Cryptography.Xml.NETSystem.Security.Cryptography.XmlReal-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
Executive Summary:
Microsoft is releasing this security advisory to provide information about a vulnerability in System.Security.Cryptography.Xml. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
A vulnerability exists in EncryptedXml class where a buffer overflow can give an attacker to the ability to perform a Denial of Service attack.
Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/391
CVSS Details
- Version: 3.1
- Severity: High
- Score: 7.5
- Vector: 7.5: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H E:U/RL:O/RC:C
- Weakness: CWE-121 CWE-20: Stack-based Buffer Overflow Improper Input Validation
Affected Platforms
- Platforms: All
- Architectures: All
<a name="affected-packages"></a>Affected Packages
The vulnerability affects any Microsoft .NET project if it uses any of affected packages versions listed below
<a name=".NET 10"></a>.NET 10
| Package name | Affected version | Patched version |
|---|---|---|
| System.Security.Cryptography.Xml | >=10.0.0, <=10.0.5; | 10.0.6 |
<a name=".NET 9"></a>.NET 9
| Package name | Affected version | Patched version |
|---|---|---|
| System.Security.Cryptography.Xml | >=9.0.0, <=9.0.14; | 9.0.15 |
<a name=".NET 8"></a>.NET 8
| Package name | Affected version | Patched version |
|---|---|---|
| System.Security.Cryptography.Xml | >=8.0.0, <=8.0.2; | 8.0.3 |
Advisory FAQ
<a name="how-affected"></a>How do I know if I am affected?
If using a package listed in affected packages, you're exposed to the vulnerability.
<a name="how-fix"></a>How do I fix the issue?
To update the Using the System.Security.Cryptography.xml NuGet package, use one of the following methods:
NuGet Package Manager UI in Visual Studio:
- Open your project in Visual Studio.
- Right-click on your project in Solution Explorer and select "Manage NuGet Packages..." or navigate to "Project > Manage NuGet Packages".
- In the NuGet Package Manager window, select the "Updates" tab. This tab lists packages with available updates from your configured package sources.
- Select the package(s) you wish to update. You can choose a specific version from the dropdown or update to the latest available version.
- Click the "Update" button.
Using the NuGet Package Manager Console in Visual Studio:
- Open your project in Visual Studio.
- Navigate to "Tools > NuGet Package Manager > Package Manager Console".
- To update a specific package to its latest version, use the following Update-Package command:
Update-Package -Id System.Security.Cryptography.Xml
Using the .NET CLI (Command Line Interface):
- Open a terminal or command prompt in your project's directory.
- To update a specific package to its latest version, use the following add package command:
dotnet add package System.Security.Cryptography.Xml
Once you have updated the nuget package reference you must recompile and deploy your application. Additionally we recommend you update your runtime and/or SDKs, but it is not necessary to patch the vulnerability.
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
Acknowledgements
Ludvig Pedersen
Revisions
V1.0 (April 14, 2026): Advisory published.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | System.Security.Cryptography.Xml | ≥ 10.0.0&&< 10.0.6 | 10.0.6dotnet add package System.Security.Cryptography.Xml --version 10.0.6 |
| .NETNuGet | System.Security.Cryptography.Xml | ≥ 9.0.0&&< 9.0.15 | 9.0.15dotnet add package System.Security.Cryptography.Xml --version 9.0.15 |
| .NETNuGet | System.Security.Cryptography.Xml | ≥ 8.0.0&&< 8.0.3 | 8.0.3dotnet add package System.Security.Cryptography.Xml --version 8.0.3 |
Affected Products
.netmicrosoftvisual studio 2022microsoftvisual studio 2026microsoftDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for System.Security.Cryptography.Xml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update System.Security.Cryptography.Xml to 10.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6588-8gv4-xfgh is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
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.
This is an Important denial of service vulnerability in .NET, affecting Red Hat Enterprise Linux and Fedora. The flaw, a stack overflow in EncryptedKey nested decryption, could allow an attacker to cause a denial of service.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for GHSA-6588-8gv4-xfgh (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | dotnet10.0-0:10.0.106-1.el10_1 | RHSA-2026:8467 |
| Red Hat Enterprise Linux 10 | dotnet8.0-0:8.0.126-1.el10_1 | RHSA-2026:8470 |
| Red Hat Enterprise Linux 10 | dotnet9.0-0:9.0.116-1.el10_1 | RHSA-2026:8472 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | dotnet9.0-0:9.0.116-1.el10_0 | RHSA-2026:13280 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | dotnet8.0-0:8.0.126-1.el10_0 | RHSA-2026:13281 |
| Red Hat Enterprise Linux 8 | dotnet8.0-0:8.0.126-1.el8_10 | RHSA-2026:8468 |
| Red Hat Enterprise Linux 8 | dotnet10.0-0:10.0.106-1.el8_10 | RHSA-2026:8473 |
| Red Hat Enterprise Linux 8 | dotnet9.0-0:9.0.116-1.el8_10 | RHSA-2026:8475 |
Frequently Asked Questions
Is GHSA-6588-8gv4-xfgh in your dependencies?
Find it across NuGet, including transitive dependencies.