What is CVE-2026-21516?

CVE-2026-21516 is a high-severity vulnerability in Microsoft GitHub Copilot, classified under Command Injection. CVSS score: 8.8/10. Published 2026-02-10.

How severe is CVE-2026-21516?

High severity. CVSS v3 base score is 8.8 out of 10.

RCE in Microsoft GitHub Copilot

CVE-2026-21516

Improper neutralization of special elements used in a command ('command injection') in Github Copilot allows an unauthorized attacker to execute code over a network.

Vulnerability class: Command Injection (OS Command Injection)

Published 2026-02-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (55.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.000

Affected products

Microsoft GitHub Copilot
Microsoft GitHub Copilot Plugin For Jetbrains Ides — versions 1.0.0

Weakness classification (CWE)

CWE-77 — Command Injection

References

GitHub Copilot for Jetbrains Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21516?: CVE-2026-21516 is a high-severity vulnerability in Microsoft GitHub Copilot, classified under Command Injection. CVSS score: 8.8/10. Published 2026-02-10.
How severe is CVE-2026-21516?: High severity. CVSS v3 base score is 8.8 out of 10.