CVE-2026-25592Network attack vector

Host file write via AI-controlled download path

Published Feb 6, 2026 · Updated Feb 6, 2026

Path traversal in Microsoft Semantic Kernel .NET SDK before 1.71.0 allows remote authenticated users to write files on the host. SessionsPythonPlugin exposes DownloadFileAsync as an AI-callable KernelFunction and passes its model-controlled localFilePath to File.WriteAllBytes without validation. An attacker who can inject a prompt into an agent using the plugin can escape the container boundary and place a payload for execution, including in the Windows Startup folder.

CVSS severity9.9
Critical
EPSS probability2.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Path traversal in Microsoft Semantic Kernel .NET SDK before 1.71.0 allows remote authenticated users to write files on the host. SessionsPythonPlugin exposes DownloadFileAsync as an AI-callable KernelFunction and passes its model-controlled localFilePath to File.WriteAllBytes without validation. An attacker who can inject a prompt into an agent using the plugin can escape the container boundary and place a payload for execution, including in the Windows Startup folder.

The record

CVE
CVE-2026-25592
Published
Feb 6, 2026
Updated
Feb 6, 2026
Vendor
Microsoft
Product
Semantic Kernel
Classifications
CWE-22, T1547.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.70.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Semantic Kernelversion=< 1.70.0

Published CVSS scores

9.9GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1547.001Registry Run Keys / Startup Folder

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo