Vulnerability · Published Jun 22, 2026 · Assigned by mitre

CVE-2025-66389

High 7.5

In plain English

A high-severity security flaw in the affected software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 68% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)1.2%top 32.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

Weakness: CWE-552 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

https://github.com/microsoft/vscode-copilot-chat/
https://github.com/microsoft/vscode/blob/03baef1008086ed4960042fa463e570072173bb5/src/vs/workbench/contrib/chat/electron-browser/tools/fetchPageTool.ts#L152
https://blindcyber.com/2025/10/28/copilot-fun/