CVE-2026-87697 .NET Remote Code Execution Vulnerability
High 8.8
Published
Updated
Check this codebase for CVE-2026-87697 and fix it if it is affected.
What it is: CVE-2026-87697 is a high-severity unsafe deserialization vulnerability in Microsoft .NET 10.0 runtime, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-87697 in the wild and no public exploit code.
Affected packages and fixed versions:
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 10.0.0; fixed in 10.0.13
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 10.0.0; fixed in 10.0.13
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 11.0.0-preview.1; fixed in 11.0.0-rc.2
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 11.0.0-preview.1; fixed in 11.0.0-rc.2
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 8.0.0; fixed in 8.0.32
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 8.0.0; fixed in 8.0.32
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 9.0.0; fixed in 9.0.21
- Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): affected from 9.0.0; fixed in 9.0.21
- Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): affected from 10.0.0; fixed in 10.0.13
- Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): affected from 10.0.0; fixed in 10.0.13
- Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): affected from 11.0.0-preview.1; fixed in 11.0.0-rc.2
- Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): affected from 11.0.0-preview.1; fixed in 11.0.0-rc.2
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-2026-87697/ (Markdown: https://insights.sbomify.com/CVE-2026-87697/index.md)
An unauthorized attacker can execute arbitrary code over the network due to unsafe deserialization in .NET.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-87697?
CVE-2026-87697 is a high-severity unsafe deserialization vulnerability in Microsoft .NET 10.0 runtime, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Deserialization of untrusted data in .NET allows an unauthorized attacker to execute code over a network.
Weakness: CWE-502
Which versions are affected by CVE-2026-87697?
24 open source packages ship an affected version, including Microsoft.WindowsDesktop.App.Runtime.win-arm64, Microsoft.WindowsDesktop.App.Runtime.win-x64 and Microsoft.WindowsDesktop.App.Runtime.win-x86.
| Package | Affected | Fixed in |
|---|---|---|
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 10.0.0 | 10.0.13 |
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 10.0.0 | 10.0.13 |
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 8.0.0 | 8.0.32 |
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 8.0.0 | 8.0.32 |
18 more packages
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 9.0.0 | 9.0.21 |
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet | From 9.0.0 | 9.0.21 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 10.0.0 | 10.0.13 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 10.0.0 | 10.0.13 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 8.0.0 | 8.0.32 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 8.0.0 | 8.0.32 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 9.0.0 | 9.0.21 |
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet | From 9.0.0 | 9.0.21 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 10.0.0 | 10.0.13 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 10.0.0 | 10.0.13 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 8.0.0 | 8.0.32 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 8.0.0 | 8.0.32 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 9.0.0 | 9.0.21 |
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet | From 9.0.0 | 9.0.21 |
How do I fix CVE-2026-87697?
Upgrade Microsoft.WindowsDesktop.App.Runtime.win-arm64 to a fixed version for your release line: 10.0.13, 11.0.0-rc.2, 8.0.32 or 9.0.21.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-87697 being exploited?
There is no known exploitation of CVE-2026-87697 in the wild and no public exploit code.
Sources
Also known as GHSA-c27m-942f-rcfh, UBUNTU-CVE-2026-87697.