# CVE-2026-58626 — Microsoft Windows 10 Version 21H2

> As of 2026-10-08, CVE-2026-58626 is a HIGH-severity vulnerability in Microsoft Windows 10 Version 21H2, CVSS v3.1 8.8, EPSS 0.9% (58.9th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-58626, most recently “Microsoft July 2026 Patch Tuesday: 570 Vulnerabilities Fixed, Including 2 Actively Exploited Zero-Days (CVE-2026-56164, CVE-2026-56155)”.

**Last updated:** 2026-10-08

## What is CVE-2026-58626?

Use after free in Windows Remote Desktop Services allows an authorized attacker to execute code over a network.

The record classifies CVE-2026-58626 under weakness class [CWE-416](https://intel.threadlinqs.com/cwe/CWE-416). 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. 8 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 106 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 8.8 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **EPSS (FIRST):** 0.9% probability of exploitation in the next 30 days, higher than 58.9% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-14, last modified 2026-10-08

## Is CVE-2026-58626 being exploited?

It currently carries a trending score of 28 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Microsoft](https://intel.threadlinqs.com/vendors/microsoft): Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows Server 2022, Windows Server 2025, Windows Server 2025 (Server Core installation)

## How to fix CVE-2026-58626

No vendor patch reference has been recorded for CVE-2026-58626 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-2026-58626

1 tracked threat in the Threadlinqs corpus references CVE-2026-58626, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Microsoft July 2026 Patch Tuesday: 570 Vulnerabilities Fixed, Including 2 Actively Exploited Zero-Days (CVE-2026-56164, CVE-2026-56155)](https://intel.threadlinqs.com/threat/TL-2026-1325) — CRITICAL · 2026-07-14

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10.

**Vendor advisory and patch**

- [msrc.microsoft.com — vendor advisory](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58626)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-58626
Full detection coverage and IOCs for threats exploiting CVE-2026-58626 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp