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CVE intelligence

CVE-2026-66306

Vulnerability intelligence

Published Sep 8, 2026Sources checked Oct 28, 2026
6.5MEDIUMCVSS out of 10
What this means

Review the available evidence

CVE-2026-66306 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

Install KB5123300. Install KB5123287. Install KB5123301.

Vendor-listed releases

  • 7.0.2046.569
  • 7.0.2046.879
  • 6.0.9319.885
CISA KEVNot listedBased on the latest collected catalog
EPSS0.9%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview

What is CVE-2026-66306?

Generation of error message containing sensitive information in Skype for Business allows an unauthorized attacker to disclose information over a network.

Source: NVD