CVE intelligence

CVE-2026-58649

Vulnerability intelligence

Published Sep 8, 2026Sources checked Oct 27, 2026

6.5MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-58649 and is rated Medium severity with a CVSS score of 6.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Sep 8, 2026

Vendor remediation details

Release Notes Install KB5126104. Install KB5126105. Install KB5126106.

Vendor-listed releases

17.14.40
11.0 RC1
8.0.130, 8.0.424
9.0.120, 9.0.317
18.9.3
10.0.111, 10.0.400

CISA KEVNot listedBased on the latest collected catalog

EPSS0.4%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-58649?

Origin validation error in .NET allows an unauthorized attacker to disclose information over a network.

Source: NVD