cbcvebase.
CVE-2026-26030
published 2026-02-19

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…

PriorityP270critical9.9CVSS 3.1
AVNACLPRLUINSCCHIHAH
EPSS
2.91%
85.3th percentile
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

4 ranges
VendorProductVersion rangeFixed in
microsoftsemantic-kernel< 1.39.41.39.4
microsoftsemantic-kernel>= 0 < 1.39.41.39.4
microsoftsemantic_kernel< 1.39.41.39.4
msrcmicrosoft_semantic_kernel_python_sdk

Detection & IOCsextracted from sources · hover to see the quote

urlhttps://github.com/microsoft/semantic-kernel/archive/refs/tags/python-1.39.4.zip
urlhttps://github.com/microsoft/semantic-kernel/releases/tag/python-1.39.4
urlhttps://github.com/microsoft/semantic-kernel/archive/refs/tags/python-1.39.4.tar.gz
  • The vulnerability requires only low privileges (any authenticated user) and results in a scope change — flag anomalous process spawning from the Semantic Kernel Python SDK process as a high-priority indicator.
  • CVE-2026-26030 is specifically within the InMemoryVectorStore filter functionality of the Semantic Kernel Python SDK; audit code paths that pass user-controlled input into InMemoryVectorStore filter parameters.
  • CVE-2026-26030 was described alongside CVE-2026-25592 as part of a chain that can turn a prompt injection into host-level remote code execution; correlate both CVEs when investigating Semantic Kernel RCE incidents.
  • ·The vulnerability only affects Semantic Kernel Python SDK versions prior to 1.39.4; the fixed version is python-1.39.4. Verify the installed package version before applying detection logic.
  • ·The vulnerable component is InMemoryVectorStore; applications that do not expose InMemoryVectorStore filter functionality to untrusted network input are not directly exploitable via this path.
  • ·Exploitation requires the application to expose filter string submission to untrusted users over the network; internal-only deployments with no untrusted input path have reduced exposure.

CVSS provenance

nvdv3.19.9CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
vendor_msrc9.9CRITICAL
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