# CVE-2026-96222: Active Directory Federation Services (AD FS) Spoofing Vulnerability

> An attacker can spoof identities in Active Directory Federation Services due to improper certificate validation, bypassing security controls.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** BIT-dotnet-2026-96222, BIT-dotnet-sdk-2026-96222, ECHO-e782-b942-c9ee, GHSA-vrv5-2jg9-4mmr, MINI-7h3g-hmmq-cx39, MINI-g72r-ph6p-v357, ROOT-APP-NUGET-CVE-2026-96222, UBUNTU-CVE-2026-96222

## What is CVE-2026-96222?

CVE-2026-96222 is a high-severity vulnerability in Microsoft .Net, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper certificate validation in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-96222?

4 open source packages ship an affected version, including System.Security.Cryptography.Xml, dotnet and dotnet-sdk. It affects 11 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `System.Security.Cryptography.Xml` | NuGet | From 8.0.0 | 8.0.5 |
| `System.Security.Cryptography.Xml` | NuGet | From 8.0.0 | 8.0.5 |
| `dotnet` | Bitnami | From 8.0.0 | 8.0.5 |
| `dotnet-sdk` | Bitnami | From 8.0.0 | 8.0.5 |

Products: Microsoft .Net, Microsoft .Net Framework, Microsoft Visual Studio 2022, Microsoft Visual Studio 2026, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2025.

## How do I fix CVE-2026-96222?

Upgrade System.Security.Cryptography.Xml to 8.0.5 or later.

## Is CVE-2026-96222 being exploited?

There is no known exploitation of CVE-2026-96222 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft .Net

- [CVE-2024-43498](https://insights.sbomify.com/CVE-2024-43498/): .NET and Visual Studio Remote Code Execution Vulnerability (critical 9.8)
- [CVE-2024-0057](https://insights.sbomify.com/CVE-2024-0057/): NET, .NET Framework, and Visual Studio Security Feature Bypass Vulnerability (critical 9.1)
- [CVE-2026-96957](https://insights.sbomify.com/CVE-2026-96957/): .NET Security Feature Bypass Vulnerability (high 8.8)
- [CVE-2026-69439](https://insights.sbomify.com/CVE-2026-69439/): .NET and Visual Studio Elevation of Privilege Vulnerability (high 8.8)
- [CVE-2026-71328](https://insights.sbomify.com/CVE-2026-71328/): .NET and Visual Studio Remote Code Execution Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96222 and fix it if it is affected.

What it is: CVE-2026-96222 is a high-severity vulnerability in Microsoft .Net, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-96222 in the wild and no public exploit code.

Affected packages and fixed versions:
- System.Security.Cryptography.Xml (NuGet): affected from 8.0.0; fixed in 8.0.5
- System.Security.Cryptography.Xml (NuGet): affected from 8.0.0; fixed in 8.0.5
- dotnet (Bitnami): affected from 8.0.0; fixed in 8.0.5
- dotnet-sdk (Bitnami): affected from 8.0.0; fixed in 8.0.5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-96222/ (Markdown: https://insights.sbomify.com/CVE-2026-96222/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96222
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96222
- OSV: https://osv.dev/vulnerability/CVE-2026-96222

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-96222/
Summaries are generated and may contain mistakes; the official description above is the record.