---
title: "CVE-2026-26030: Microsoft Semantic Kernel InMemoryVectorStore filter functionality vulnerable to remote code execution"
url: https://erroneo.us/security/cve/CVE-2026-26030/
description: "CVE-2026-26030 (semantic-kernel (PyPI)): Semantic Kernel, Microsoft's semantic kernel Python SDK, has a remote code execution vulnerability in versions…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-02-19
date_modified: 2026-06-08
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-26030"
kev: false
cvss: 10
epss: 0.04134
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-26030: Microsoft Semantic Kernel InMemoryVectorStore filter functionality vulnerable to remote code execution

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 4.1% , percentile 91: FIRST’s model estimates a 4.1% chance of exploitation activity in the next 30 days, higher than 91% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes semantic-kernel (PyPI) < 1.39.4, fixed in 1.39.4 . Check your lockfile, including transitive dependencies.

## What it is

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 packages

- PyPI `semantic-kernel` < 1.39.4 → fixed: 1.39.4

## Affected products (CVE record)

- microsoft semantic-kernel: < 1.39.4

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 4.13% probability of exploitation activity in the next 30 days; percentile 91.

## Sources

- [GitHub Advisory GHSA-xjw9-4gw8-4rqx](https://github.com/advisories/GHSA-xjw9-4gw8-4rqx)
- [CVE.org record CVE-2026-26030](https://www.cve.org/CVERecord?id=CVE-2026-26030)
- [NVD entry CVE-2026-26030](https://nvd.nist.gov/vuln/detail/CVE-2026-26030)
- [github.com](https://github.com/microsoft/semantic-kernel/security/advisories/GHSA-xjw9-4gw8-4rqx)
- [github.com](https://github.com/microsoft/semantic-kernel/pull/13505)
- [github.com](https://github.com/microsoft/semantic-kernel/releases/tag/python-1.39.4)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/semantic-kernel/PYSEC-2026-163.yaml)

---
Source page: https://erroneo.us/security/cve/CVE-2026-26030/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt