CVE-2026-26030: Microsoft Semantic Kernel

Critical severity, CVSS 9.9. EPSS: 3.8% chance of exploitation in the next 30 days.

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. The problem has been fixed in version `python-1.39.4`. Users should upgrade this version or higher. As a workaround, avoid using `InMemoryVectorStore` for production scenarios.

Affected products

• Microsoft Semantic Kernel: before 1.39.4 (fixed in 1.39.4)

Published 2026-02-19. Last modified 2026-06-17.