CVE intelligence

CVE-2026-23666

Vulnerability intelligence

Published Apr 14, 2026Sources checked Nov 11, 2026

7.5HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-23666 and is rated High severity with a CVSS score of 7.5. 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: Apr 15, 2026

Vendor remediation details

Install KB5082411. Install KB5082403. Install KB5082404. Install KB5082414. Install KB5082427. Install KB5082426. Install KB5082413. Install KB5082400. Install KB5082402. Install KB5082425. Install KB5082419. Install KB5082424. Install KB5082417. Install KB5082418. Install KB5082420. Install KB5082398. Install KB5082406. Install KB5082421.

Vendor-listed releases

4.8.4801.0
2.0.50727.9068 & 3.0.30729.9065 & 4.8.4801.0
2.0.50727.9181 & 3.0.30729.9165 & 4.8.4801.0
2.0.50727.9068 & 3.0.30729.9065 & 4.7.4141.0
4.7.4141.0
2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0
2.0.50727.8982 & 3.0.30729.8976

CISA KEVNot listedBased on the latest collected catalog

EPSS1.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-23666?

Improper input validation in .NET Framework allows an unauthorized attacker to deny service over a network.

Source: NVD