Threat Intelligence / CVE / CVE-2026-26030

CVE-2026-26030 — microsoft semantic-kernel

CVSS v3.1 10 (CRITICAL) · EPSS 0.1% (higher than 27.9% of all scored CVEs) · Priority 6.1/10 · Published 2026-02-19

As of 2026-02-26, CVE-2026-26030 is a CRITICAL-severity vulnerability in microsoft semantic-kernel, CVSS v3.1 10, EPSS 0.1% (27.9th percentile). Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-26030, most recently “Microsoft Semantic Kernel Prompt-Injection-to-RCE & Arbitrary File Write — CVE-2026-26030 (InMemoryVectorStore eval) + CVE-2026-25592 (SessionsPythonPlugin)”.

Last updated: 2026-02-26

What is 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.

The record classifies CVE-2026-26030 under weakness class CWE-94. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 206 days ago.

Severity and exploitation probability

CVSS v3.1 base score
10 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS (FIRST)
0.1% probability of exploitation in the next 30 days, higher than 27.9% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
6.1/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-02-19, last modified 2026-02-26

Is CVE-2026-26030 being exploited?

It currently carries a trending score of 17 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-26030

No vendor patch reference has been recorded for CVE-2026-26030 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-26030

2 tracked threats in the Threadlinqs corpus reference CVE-2026-26030, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-26030 are available via the Threadlinqs MCP server (Purple tier). View plans →

← all vulnerabilities · Markdown version · Threadlinqs Intelligence