CVE-2026-21523

Name: CVE-2026-21523
Creator: NVD / NIST
Published: 2026-02-10T18:16:34.743+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8/10EPSS 0.79%

Last modified Jun 17, 2026

CVE-2026-21523 is a high-severity vulnerability rated 8/10 on the CVSS scale. 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.. EPSS estimates a 0.79% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.79%

51.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-367

Affected Software

Vendor	Product	Versions
Microsoft	Visual Studio Code	< 1.109.2

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21523Vendor Advisory

Timeline

Published: Feb 10, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

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.

How severe is CVE-2026-21523?

CVE-2026-21523 has a CVSS score of 8/10 (HIGH severity). The EPSS model estimates a 0.79% probability of exploitation in the next 30 days.

How do I fix CVE-2026-21523?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-21523?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST