CVE intelligence

CVE-2026-21523

Vulnerability intelligence

Published Feb 10, 2026Sources checked Oct 3, 2026

8.0HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-21523 and is rated High severity with a CVSS score of 8.0. 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

Release Notes

Vendor-listed releases

0.37.1
1.110.1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.8%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-21523?

Time-of-check time-of-use (toctou) race condition in GitHub Copilot and Visual Studio allows an authorized attacker to execute code over a network.