GHSA-55v3-xh23-96gh `auth.TokenForHost` violates GitHub host security boundary when sourcing authentication token within a codespace

• Go github.com/cli/go-gh/v2: < 2.11.1 → fixed in 2.11.1 • Go github.com/cli/go-gh: < 2.11.1 (no fix yet)

Summary A security vulnerability has been identified in `go-gh` that could leak authentication tokens intended for GitHub hosts to non-GitHub hosts when within a codespace. Details `go-gh` sources authentication tokens from different environment variables depending on the host involved: • `GITHUB_TOKEN`, `GH_TOKEN` for GitHub.com and ghe.com • `GITHUB_ENTERPRISE_TOKEN`, `GH_ENTERPRISE_TOKEN` for GitHub Enterprise Server Prior to `2.11.1`, `auth.TokenForHost` could source a token from the `GITHUB_TOKEN` environment variable for a host other than GitHub.com or ghe.com when within a codespace. In `2.11.1`, `auth.TokenForHost` will only source a token from the `GITHUB_TOKEN` environment variable for GitHub.com or ghe.com hosts. Impact Successful exploitation could send authentication token to an unintended host. Remediation and mitigation 1. Upgrade `go-gh` to `2.11.1` 2. Advise extension users to regenerate authentication tokens: • Personal access tokens • GitHub CLI OAuth app 3. Advise extension users to review their personal security log and any relevant audit logs for actions associated with their account or enterprise