Executive brief
GitHub CLI is the official command-line tool for interacting with GitHub. Versions 2.28.0 through 2.97.0 expose port-forwarded services on all network interfaces by default, allowing any host on the same local network to access services that should remain private. This unintended exposure could permit unauthorized access to services running in a Codespace, potentially compromising sensitive data or enabling malicious operations.
Technical details
The vulnerability is a network binding misconfiguration in the `gh codespace ports forward` command. When a user forwards a port from a Codespace to their local machine, the CLI creates a TCP listener bound to the wildcard address (0.0.0.0:port) instead of loopback (127.0.0.1:port), making the forwarded service reachable through all network interfaces. An adjacent network attacker (on the same LAN, VPN, or routable network) can connect to the forwarded service while the forwarding process is active. No credentials, shell access, or Codespace access is required for exploitation. The fix, released in version 2.98.0, binds to loopback by default and introduces an optional --all-interfaces flag for users who intentionally need broader exposure.
Affected products
- GitHub CLI 2.28.0 through 2.97.0
Timeline
- 2026-08-20: disclosed
- 2026-08-20: patched: Fixed in version 2.98.0