Published May 28, 2026Sources checked Nov 11, 2026
3.1LOWCVSS out of 10
What this means
Review the available evidence
CVE-2026-9959 and is rated Low severity with a CVSS score of 3.1. 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: May 29, 2026
Release Notes
Vendor-listed releases
148.0.3967.96
CISA KEVNot listedBased on the latest collected catalog
EPSS0.1%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-9959?
Race in WebRTC in Google Chrome on Windows prior to 148.0.7778.216 allowed a remote attacker to leak cross-origin data via a crafted HTML page. (Chromium security severity: High)