CVE-2026-26030: Remote Code Execution Vulnerability in Semantic Kernel Python SDK
Summary
CVE-2026-26030: Semantic Kernel, Microsoft's semantic kernel Python SDK, has a remote code execution vulnerability in versions prior to 1.39.4, specifically within the InMemoryVectorStore filter functionality. Affects semantic-kernel versions < 1.39.4. Fixed in 1.39.4. How to fix ↓
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Background
Semantic Kernel is Microsoft's semantic kernel Python SDK designed for building applications that utilize advanced AI capabilities. It provides functionalities for managing and processing vector data, enabling developers to create intelligent applications. However, certain versions of this SDK are vulnerable to a remote code execution issue, particularly in the InMemoryVectorStore filter functionality.
Vulnerability Detail
The vulnerability arises from improper handling within the InMemoryVectorStore filter functionality, allowing an attacker to execute arbitrary code remotely. This can lead to severe consequences, including unauthorized access to sensitive data and complete system compromise. The vulnerability affects all versions prior to 1.39.4, with a CVSS score of 9.9 indicating a critical severity level.
How To Fix
Latest published version: 1.45.0 as of 23 Oct 2026
pip install --upgrade "semantic-kernel==1.45.0"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
1.39.4
This is the first release that contains the fix.
pip install --upgrade "semantic-kernel==1.39.4"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, avoid using the InMemoryVectorStore functionality in production scenarios until the package is updated to a secure version.
Conclusion
The Semantic Kernel Python SDK has a critical remote code execution vulnerability that affects versions prior to 1.39.4. Users are strongly advised to upgrade to the patched version to mitigate risks. Temporary workarounds are available, but upgrading is the best long-term solution.
See every vulnerability recorded for semantic-kernel →
FAQ
The CVSS score of this vulnerability is 9.9, indicating a critical severity level.
All versions prior to 1.39.4 are affected by this vulnerability.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without any signup.
If you cannot upgrade immediately, avoid using the InMemoryVectorStore functionality in production environments as a temporary workaround.
More information can be found in the advisory database at https://github.com/pypa/advisory-database/blob/main/vulns/semantic-kernel/PYSEC-2026-163.yaml.
References
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