Customizing or disabling the firewall for GitHub Copilot

Learn how to control the domains and URLs that Copilot クラウドエージェント and Copilotコード レビュー can access.

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メモ

Firewall configuration is managed from the "Internet access" settings tab, which covers both Copilot クラウドエージェント and Copilotコード レビュー. Previous configurations saved as Actions variables will be maintained on that page.

Overview

By default, Copilot's access to the internet is limited by a firewall.

メモ

Copilotコード レビュー also supports firewall configuration, at both the organization and repository level, under its own section of the "Internet access" tab described below. This allows you to configure firewall rules for Copilotコード レビュー independently of Copilot クラウドエージェント. See GitHub Copilot を使ったコードレビュー.

Limiting internet access helps manage data exfiltration risks. Unexpected behavior from Copilot, or malicious instructions, could lead to code or other sensitive information being leaked to remote locations.

The firewall always allows access to a number of hosts that Copilot uses to interact with GitHub. By default, a recommended allowlist is also enabled to allow the agent to download dependencies.

If Copilot tries to make a request which is blocked by the firewall, a warning is added to the pull request body (for new pull requests) or to a comment (for existing pull requests). The warning shows the blocked address and the command that tried to make the request.

Screenshot of a warning from Copilot about being blocked by the firewall.

Limitations

The agent firewall has important limitations that affect its security coverage.

  • Only applies to processes started by the agent: The firewall only applies to processes started by the agent via its Bash tool. It does not apply to Model Context Protocol (MCP) servers or processes started in configured Copilot setup steps.
  • Only applies within the GitHub Actions appliance: The firewall only operates within the GitHub Actions appliance environment. It does not apply to processes running outside of this environment.
  • Bypass potential: Sophisticated attacks may bypass the firewall, potentially allowing unauthorized network access and data exfiltration.

These limitations mean that the firewall provides protection for common scenarios, but should not be considered a comprehensive security solution.

The recommended allowlist, enabled by default, allows access to:

  • Common operating system package repositories (for example, Debian, Ubuntu, Red Hat).
  • Common container registries (for example, Docker Hub, Azure Container Registry, AWS Elastic Container Registry).
  • Packages registries used by popular programming languages (C#, Dart, Go, Haskell, Java, JavaScript, Perl, PHP, Python, Ruby, Rust, Swift).
  • Common certificate authorities (to allow SSL certificates to be validated).
  • Hosts used to download web browsers for the Playwright MCP server.

For the complete list of hosts included in the recommended allowlist, see Copilot 許可リスト リファレンス.

Configuring the firewall at the organization level

Organization owners can configure all firewall settings at the organization level, for both Copilot クラウドエージェント and Copilotコード レビュー. To access the firewall settings:

  1. GitHub の右上隅にあるプロフィール画像をクリックしてから、[ Your organizations] をクリックします。

  2. 組織をクリックして選択します。

  3. Organization 名の下で、[ Settings] をクリックします。 [設定] タブが表示されない場合は、 [] ドロップダウン メニューを選び、 [設定] をクリックします。

    組織のプロファイルのタブのスクリーンショット。 [設定] タブが濃いオレンジ色の枠線で囲まれています。 In the sidebar, under "Code, planning, and automation", click Copilot, and then click Internet access.

The "Internet access" page has separate sections for Copilot クラウドエージェント and Copilotコード レビュー, so you can configure the following settings independently for each.

Enabling or disabling the firewall

警告

Disabling the firewall will allow Copilot to connect to any host, increasing risks of exfiltration of code or other sensitive information.

  1. Under "Internet access", set the Enable firewall setting to Enabled, Disabled, or Let repositories decide (default).
  1. Under "Internet access", set the Recommended allowlist setting to Enabled, Disabled, or Let repositories decide (default).

Controlling whether repositories can add custom allowlist rules

By default, repository administrators can add their own entries to the firewall allowlist. Organization owners can disable this to prevent repositories from adding custom rules.

  1. Under "Internet access", set the Allow repository custom rules setting to Enabled (default) or Disabled.

Managing the organization custom allowlist

Items added to the organization custom allowlist apply to all repositories in the organization. These items cannot be deleted at the repository level. Organization-level and repository-level rules are combined.

  1. Under "Internet access", click Organization custom allowlist.

  2. 許可リストに含めるアドレスを追加します。 以下を含めることができます。

    • ドメイン (たとえば、packages.contoso.corp)。 指定したドメインと任意のサブドメインに許可するトラフィック。

Example: packages.contoso.corp では、トラフィックは packages.contoso.corp と prod.packages.contoso.corp に許可されますが、artifacts.contoso.corpは許可されません。

  • URLs (例: https://packages.contoso.corp/project-1/)。 トラフィックは指定されたスキーム (https) とホスト (packages.contoso.corp) にのみ許可され、指定されたパスと子孫パスに制限されます。

Example: https://packages.contoso.corp/project-1/ では、https://packages.contoso.corp/project-1/ と https://packages.contoso.corp/project-1/tags/latest へのトラフィックは許可されますが、https://packages.contoso.corp/project-2、ftp://packages.contoso.corp、または https://artifacts.contoso.corp は許可されません。

  1. [ルールの追加] をクリックします。
  2. リストを検証後、[Save changes] をクリックします。

Configuring the firewall at the repository level

Repository administrators can configure firewall settings at the repository level, including enabling or disabling the firewall, enabling or disabling the recommended allowlist, and managing a custom allowlist. Depending on the organization-level configuration, some of these settings may be locked. The repository settings page also has separate sections for Copilot クラウドエージェント and Copilotコード レビュー, so you can configure these settings independently for each.

To access the firewall settings:

  1. GitHub で、リポジトリのメイン ページに移動します。

  2. リポジトリ名の下にある [Settings] をクリックします。 [設定] タブが表示されない場合は、 [] ドロップダウン メニューを選び、 [設定] をクリックします。

    タブを示すリポジトリ ヘッダーのスクリーンショット。 [設定] タブが濃いオレンジ色の枠線で強調表示されています。

  3. In the "Code & automation" section of the sidebar, click Copilot then Internet access.

Enabling or disabling the firewall

メモ

You can only change this setting at the repository level if the organization-level Enable firewall setting is set to Let repositories decide. If the organization-level setting is Enabled or Disabled, you can't change this setting for individual repositories.

  1. Toggle the Enable firewall setting on or off.

メモ

You can only change this setting at the repository level if the organization-level Recommended allowlist setting is set to Let repositories decide. If the organization-level setting is Enabled or Disabled, you can't change this setting for individual repositories.

  1. Toggle the Recommended allowlist setting on or off.

Managing the custom allowlist

メモ

You can only add custom allowlist rules at the repository level if the organization-level Allow repository custom rules setting is set to Enabled. For more information, see Controlling whether repositories can add custom allowlist rules.

  1. Click Custom allowlist.

  2. 許可リストに含めるアドレスを追加します。 以下を含めることができます。

    • ドメイン (たとえば、packages.contoso.corp)。 指定したドメインと任意のサブドメインに許可するトラフィック。

Example: packages.contoso.corp では、トラフィックは packages.contoso.corp と prod.packages.contoso.corp に許可されますが、artifacts.contoso.corpは許可されません。

  • URLs (例: https://packages.contoso.corp/project-1/)。 トラフィックは指定されたスキーム (https) とホスト (packages.contoso.corp) にのみ許可され、指定されたパスと子孫パスに制限されます。

Example: https://packages.contoso.corp/project-1/ では、https://packages.contoso.corp/project-1/ と https://packages.contoso.corp/project-1/tags/latest へのトラフィックは許可されますが、https://packages.contoso.corp/project-2、ftp://packages.contoso.corp、または https://artifacts.contoso.corp は許可されません。

  1. [ルールの追加] をクリックします。
  2. リストを検証後、[Save changes] をクリックします。

Further reading