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


- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 19 Feb 2026
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-xjw9-4gw8-4rqx, PYSEC-2026-163

## What is CVE-2026-26030?

CVE-2026-26030 is a critical vulnerability in microsoft semantic-kernel, published on 19 Feb 2026. 

### Official description

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.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-26030?

3 open source packages ship an affected version, including semantic-kernel. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `semantic-kernel` | PyPI | All versions | 1.39.4 |
| `semantic-kernel` | PyPI | All versions | 1.39.4 |
| `semantic-kernel` | PyPI | All versions | 1.39.4 |

Products: Microsoft Semantic Kernel.

## How do I fix CVE-2026-26030?

Upgrade semantic-kernel to 1.39.4 or later.

## Is CVE-2026-26030 being exploited?

There is no known exploitation of CVE-2026-26030 in the wild and no public exploit code.

Public exploit code:

- https://github.com/mbanyamer/CVE-2026-26030-Microsoft-Semantic-Kernel-1.39.4-RCE (github_poc): https://github.com/mbanyamer/CVE-2026-26030-Microsoft-Semantic-Kernel-1.39.4-RCE
- Ethical, network-isolated Docker lab reproducing CVE-2026-26030 — Semantic Kernel in-memory vector store filter eval() RCE (patched in 1.39.4) (github_poc): https://github.com/InertFluid/sk-cve-2026-26030-lab

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26030 and fix it if it is affected.

What it is: CVE-2026-26030 is a critical vulnerability in microsoft semantic-kernel, published on 19 Feb 2026. 
Exploitation: There is no known exploitation of CVE-2026-26030 in the wild and no public exploit code.

Affected packages and fixed versions:
- semantic-kernel (PyPI): affected all versions; fixed in 1.39.4
- semantic-kernel (PyPI): affected all versions; fixed in 1.39.4
- semantic-kernel (PyPI): affected all versions; fixed in 1.39.4

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-26030/ (Markdown: https://insights.sbomify.com/CVE-2026-26030/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26030
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26030
- OSV: https://osv.dev/vulnerability/CVE-2026-26030

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26030/
Summaries are generated and may contain mistakes; the official description above is the record.