Path Traversal in Microsoft Semantic-Kernel

CVE-2026-25592

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.022 (81.6th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-25592: held from 0.024 to 0.022.

EPSS over last 30 days · oldest: 0.024 · newest: 0.022 · change: -0.003

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-25592?
CVE-2026-25592 is a critical-severity vulnerability in Microsoft Semantic-Kernel, classified under Path Traversal. CVSS score: 9.9/10. Published 2026-02-06.
How severe is CVE-2026-25592?
Critical severity. CVSS v3 base score is 9.9 out of 10.