CVSS 3.1
9.9 criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HCVE-2026-25592
Critical (9.9). EPSS 2.6% chance of exploitation in the next 30 days. Fixed in semantic-kernel 1.39.3.
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.
Severity
- EPSS
- 2.6% chance of exploitation in the next 30 days; higher than 85% of CVEs (scores of 2026-10-31)
- CWE
- CWE-22
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-2ww3-72rp-wpp4 | PyPI | semantic-kernel | <1.39.3 | 1.39.3 |
| GHSA-2ww3-72rp-wpp4 | NuGet | Microsoft.SemanticKernel.Core | <1.71.0 | 1.71.0 |
| PYSEC-2026-531 | PyPI | semantic-kernel | <1.39.3 | 1.39.3 |
References
- https://github.com/microsoft/semantic-kernel/blob/main/dotnet/samples/Demos/CodeInterpreterPlugin/Program.cs#L61-L64
- https://github.com/microsoft/semantic-kernel/pull/13478/changes#diff-88d3cacba2bfa84eef8f2aa171b34f9940338cbb784a3ffc49f5fe3af1b8943d
- https://github.com/microsoft/semantic-kernel/security/advisories/GHSA-2ww3-72rp-wpp4