CVE-2026-25592 Semantic Kernel has an Arbitrary File Write via AI Agent Function Calling in .NET SDK
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-25592?
CVE-2026-25592 is a critical vulnerability in microsoft semantic-kernel, published on 6 Feb 2026.
Official description
Semantic Kernel is an SDK used to build, orchestrate, and deploy AI agents and multi-agent systems. Prior to 1.71.0, an Arbitrary File Write vulnerability has been identified in Microsoft's Semantic Kernel .NET SDK, specifically within the SessionsPythonPlugin. The problem has been fixed in Microsoft.SemanticKernel.Core version 1.71.0. As a mitigation, users can create a Function Invocation Filter which checks the arguments being passed to any calls to DownloadFileAsync or UploadFileAsync and ensures the provided localFilePath is allow listed.
Weakness: CWE-22
Which versions are affected by CVE-2026-25592?
5 open source packages ship an affected version, including semantic-kernel and Microsoft.SemanticKernel.Core.
| Package | Affected | Fixed in |
|---|---|---|
semantic-kernel PyPI | All versions | 1.39.3 |
semantic-kernel PyPI | All versions | 1.39.3 |
semantic-kernel PyPI | All versions | 1.39.3 |
Microsoft.SemanticKernel.Core NuGet | All versions | 1.71.0 |
Microsoft.SemanticKernel.Core NuGet | All versions | 1.71.0 |
How do I fix CVE-2026-25592?
Upgrade semantic-kernel to 1.39.3 or later.
Is CVE-2026-25592 being exploited?
There is no known exploitation of CVE-2026-25592 in the wild and no public exploit code.
Sources
Also known as GHSA-2ww3-72rp-wpp4, PYSEC-2026-531.