PCS (Pacemaker Configuration System) has an arbitrary file read vulnerability in the `pcs host auth --token <path>` command path. When a non-root user in the 'haclient' group runs this command, the `_non_root_run()` function in `pcs/app.py` forwards it to the locally running pcsd daemon via HTTP POST to `/run_pcs`. The pcsd daemon (running as root) matches the command against its allowed_commands list in `pcsd/pcsd.rb` (`['host', 'auth', '...']`) with no restriction on `--token`, and re-executes PCS as root. This causes `utils.get_token_from_file()` in `pcs/utils.py` to open and read the attacker-specified file path with root privileges, reading up to 256 bytes. The file contents are base64-encoded and stored as a token in the known-hosts configuration file. The attacker can exfiltrate the file contents by triggering node communication (e.g., `pcs pcsd status`) and intercepting the HTTP Cookie header containing the base64-encoded token.

Affected: PCS versions from 0.10.8 onwards (introduced in commit 9178b78d11baa70e700a5c0d9fc1c17f27d452fa). RHEL 8.4+, RHEL 9.0+, and RHEL 10.0+ ship affected PCS versions.

Fix: Upstream patch attached to PSIRTSUPT-22935 (commit b41eaf3c6e2ecfc575c42442fb02b8ef05b4dd6a, not yet on public GitHub main). Blocks `pcs host auth --token` for non-root users in both `pcs/app.py` and `pcsd/pcsd.rb`.

Reporter: Peter Romancik (PCS upstream developer, Red Hat).
PSIRT ticket: PSIRTSUPT-22935