RCE in Microsoft Semantic-Kernel

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. 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.

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.037 (88.6th percentile) — read the EPSS interpretation.

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.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-26030?
CVE-2026-26030 is a critical-severity vulnerability in Microsoft Semantic-Kernel, classified under Code Injection. CVSS score: 9.9/10. Published 2026-02-19.
How severe is CVE-2026-26030?
Critical severity. CVSS v3 base score is 9.9 out of 10.
Is CVE-2026-26030 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.