What is CVE-2025-66389?

CVE-2025-66389 is a high-severity vulnerability in Microsoft Github_copilot, classified under Files or Directories Accessible to External Parties. CVSS score: 7.5/10. Published 2026-06-22.

How severe is CVE-2025-66389?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Microsoft Github_copilot

CVE-2025-66389

GitHub Copilot 1.372.0 allows filesystem access outside of a workspace folder (without user approval) via a file-handler URI parameter to fetch_webpage. Therefore, exfiltration could occur if there is indirect prompt injection.

EPSS: 0.009 (57.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Microsoft Github_copilot — versions 1.372.0
N/a — versions n/a

Weakness classification (CWE)

CWE-552 — Files or Directories Accessible to External Parties

References

cve@mitre.org (Product)
cve@mitre.org (Product)
cve@mitre.org (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2025-66389?: CVE-2025-66389 is a high-severity vulnerability in Microsoft Github_copilot, classified under Files or Directories Accessible to External Parties. CVSS score: 7.5/10. Published 2026-06-22.
How severe is CVE-2025-66389?: High severity. CVSS v3 base score is 7.5 out of 10.