What is the CVSS score of CVE-2026-26030?

CVE-2026-26030 has a CVSS 3.1 base score of 9.9 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Is there a public PoC exploit available for CVE-2026-26030?

Yes, a public proof-of-concept exploit is available for CVE-2026-26030. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-26030?

Within 24 hours: Identify all systems and applications using Semantic Kernel Python SDK versions prior to 1.39.4 and isolate affected systems from production networks if possible. Within 7 days: Apply vendor patch to upgrade all instances to version 1.39.4 or later, beginning with critical production systems. Within 30 days: Conduct security audit of affected systems for indicators of compromise and review access logs for suspicious activity dating back 90 days.

Semantic Kernel CVE-2026-26030

CRITICAL

Code Injection (CWE-94)

2026-02-19 security-advisories@github.com

GHSA-xjw9-4gw8-4rqx

RCE Python Linux Microsoft AI / ML Semantic Kernel

9.9

CVSS 3.1 · GitHub Advisory

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Authenticate to application using Semantic Kernel
Exploit

Craft malicious filter input for InMemoryVectorStore
Impact

Execute arbitrary code via unsafe deserialization

Vulnerability Assessment

Weakness	CWE CWE-94 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V1 - Encoding and Sanitization Code injection prevention, sandbox exec MITRE ATT&CK 2 techniques across 2 tactics: Execution, Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	Microsoft Semantic Kernel Python SDK versions prior to 1.39.4 with InMemoryVectorStore filter functionality enabled in production. Requires valid user credentials (PR:L) to submit crafted filter queries.
Impact	CVSS 9.9. Semantic Kernel is used to build AI applications — RCE exposes all connected AI services and data.
Exploit ScenarioDerived	Attacker exploits code injection in Semantic Kernel to execute code with access to AI service keys, databases, and connected systems.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.

Patch available 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Remote code execution in Microsoft Semantic Kernel Python SDK before 1.39.4. Code injection in the AI orchestration framework. Patch available.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 22:03 CVSS 9.9

RCE in Microsoft Semantic Kernel Python SDK.

RemediationAI

Update to Semantic Kernel 1.39.4.

Affected Packages

pypi semantic-kernel fix: 1.39.4

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in pypi

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

CWE-94 code injection in Microsoft's AI orchestration SDK for building AI agents.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 9.9 CRITICAL

AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch released

Mar 03, 2026 - 16:32 nvd

Patch available

CVE Published

Feb 19, 2026 - 17:24 nvd

CRITICAL 9.9

DescriptionGitHub Advisory

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.

Executive ViewAI

Why It Matters

Microsoft's Semantic Kernel Python SDK contains a critical remote code execution vulnerability (CVSS 9.9) affecting versions before 1.39.4. Any organization using this SDK in production environments faces immediate risk of unauthorized code execution and complete system compromise. A vendor patch is available and must be deployed urgently.

Business Impact: Severe

Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score

0.1%

Top 72% exploitable

Threat Intel

1 source

Exploit

POC

Public exploit code exists

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS GHSA

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV No

Public POC Yes

EPSS 0.1%

Patch available Yes

Active threat No

Deciding rule

CRITICAL severity + public POC available

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.