CVE-2026-25592
Semantic Kernel has an Arbitrary File Write via AI Agent Function Calling in .NET SDK
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Semantic Kernel has an Arbitrary File Write via AI Agent Function Calling in .NET SDK
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.
- Record
CVE-2026-25592- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2026-5582
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.
- Record
EUVD-2026-5582- CVSS 3.1
- 10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2ww3-72rp-wpp4
Semantic Kernel has Arbitrary File Write via AI Agent Function Calling in .NET SDK
Impact
What kind of vulnerability is it? Who is impacted?
An Arbitrary File Write vulnerability has been identified in Microsoft's Semantic Kernel .NET SDK, specifically within the SessionsPythonPlugin.
Developers who have built applications which include Microsoft's Semantic Kernel .NET SDK and are using the SessionsPythonPlugin
Patches
Has the problem been patched? What versions should users upgrade to? The problem has been fixed in Microsoft.SemanticKernel.Plugins.Core version 1.71.0. Users should upgrade to version 1.71.0 or higher.
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
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.
References
Are there any links users can visit to find out more?
- Record
GHSA-2ww3-72rp-wpp4- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-25592- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
Semantic Kernel has an Arbitrary File Write via AI Agent Function Calling in .NET SDK
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.
- Record
CVE-2026-25592- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVGHSA-2ww3-72rp-wpp4
Semantic Kernel has Arbitrary File Write via AI Agent Function Calling in .NET SDK
Impact
What kind of vulnerability is it? Who is impacted?
An Arbitrary File Write vulnerability has been identified in Microsoft's Semantic Kernel .NET SDK, specifically within the SessionsPythonPlugin.
Developers who have built applications which include Microsoft's Semantic Kernel .NET SDK and are using the SessionsPythonPlugin
Patches
Has the problem been patched? What versions should users upgrade to? The problem has been fixed in Microsoft.SemanticKernel.Plugins.Core version 1.71.0. Users should upgrade to version 1.71.0 or higher.
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
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.
References
Are there any links users can visit to find out more?
- Record
GHSA-2ww3-72rp-wpp4- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVPYSEC-2026-531
Semantic Kernel has Arbitrary File Write via AI Agent Function Calling in .NET SDK
Impact
What kind of vulnerability is it? Who is impacted?
An Arbitrary File Write vulnerability has been identified in Microsoft's Semantic Kernel .NET SDK, specifically within the SessionsPythonPlugin.
Developers who have built applications which include Microsoft's Semantic Kernel .NET SDK and are using the SessionsPythonPlugin
Patches
Has the problem been patched? What versions should users upgrade to? The problem has been fixed in Microsoft.SemanticKernel.Plugins.Core version 1.71.0. Users should upgrade to version 1.71.0 or higher.
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
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.
References
Are there any links users can visit to find out more?
- Record
PYSEC-2026-531- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
semantic-kernelPyPI |
before 1.39.3 | 1.39.3 |
Microsoft.SemanticKernel.CoreNuGet |
before 1.71.0 | 1.71.0 |
semantic-kernelPyPI |
before 1.39.3, plus listed versions 0.0.1.dev00.1.0.dev00.2.0.dev00.2.1.dev00.2.2.dev0 Show 45 moreShow less0.2.3.dev00.2.4.dev00.2.5.dev00.2.6.dev00.2.7.dev00.2.8.dev00.2.9.dev00.3.0.dev00.3.1.dev00.3.10.dev00.3.11.dev00.3.12.dev00.3.13.dev00.3.14.dev00.3.15.dev00.3.2.dev00.3.3.dev00.3.4.dev00.3.5.dev00.3.6.dev00.3.7.dev00.3.8.dev00.3.9.dev00.4.0.dev00.4.1.dev00.4.2.dev00.4.3.dev00.4.4.dev00.4.5.dev00.4.6.dev00.4.7.dev00.5.0.dev00.5.1.dev00.9.0b10.9.1b10.9.2b10.9.3b10.9.4b10.9.5b10.9.6b10.9.7b10.9.8b10.9.9b11.0.01.0.0rc1 |
1.39.3 |
Microsoft.SemanticKernel.CoreNuGet |
before 1.71.0, plus listed versions 0.12.207.1-preview0.13.277.1-preview0.13.442.1-preview0.14.547.1-preview0.15.230531.5-preview Show 45 moreShow less0.15.230609.2-preview0.15.231219.1-preview0.16.230615.1-preview0.17.230626.1-preview1.0.0-beta11.0.0-beta21.0.0-beta31.0.0-beta41.0.0-beta51.0.0-beta61.0.0-beta71.0.0-beta81.0.0-rc11.0.0-rc21.0.0-rc31.0.0-rc41.0.11.1.01.10.01.11.01.11.11.12.01.13.01.14.01.14.11.15.01.15.11.16.01.16.11.16.21.17.01.17.11.17.21.18.0-rc1.18.1-rc1.18.21.19.01.2.01.20.01.21.01.21.11.22.01.23.01.24.01.24.1 |
1.71.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-25592 is a critical vulnerability (CVSS 10.0) in Microsoft Semantic-kernel, published February 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.52%, the 84th percentile. Fixed in semantic-kernel 1.39.3.
References
github.com/microsoft/semantic-kernel/security/advisories/GHSA-2ww3-72rp-wpp4
nvd.nist.gov/vuln/detail/CVE-2026-25592
pypi.org/project/semantic-kernel
Left out here: 138 versions. The JSON record has them.