Please report suspected vulnerabilities privately through GitHub's private vulnerability reporting on this repository (Security → Report a vulnerability). Do not open a public issue for anything you believe has security impact.

Pre-1.0, only the latest release receives security fixes.

Released wheels statically bundle libre, libbaresip, libopus, libvpx, and libg722, and carry OpenSSL with them — Linux wheels additionally bundle ALSA's libasound. A security advisory in any of these triggers a patch release of baresip-python with the updated dependency, independent of the normal release cadence — the policy and pinned versions live in docs/UPGRADING.md. If you deploy the wheels, you patch these libraries by upgrading baresip-python, not through your system package manager.

A registered SIP user agent is a server as well as a client. Once your process holds a socket on a publicly addressable host, it will receive traffic you did not invite: scanners (SIPVicious and friends) probing for open relays, and unsolicited INVITEs from strangers. Plan for that:

• Bind deliberately. Pin the stack to the interface you mean — runtime.start(Config(net_interface=...)), with a sip_listen line in Config(extra_config_text=...) for direct-mode binds — exactly as the bundled examples pin themselves to loopback for the bench. Do not let a process meant for one network listen on all of them.
• The default posture is registrar-only. A user agent that registers to your SIP server and dials out needs no exposure to anyone but that server; put it behind the same firewalling you would give any internal service, and let the registrar be the party that faces the world.
• Screen inbound calls in code. on_incoming hands your callback the caller's URI, the SIP Call-ID, and any allowlisted headers before the call is answered — the callback's answer()-or-reject() decision is your admission control. Reject what you do not recognize; an unanswered stranger costs you nothing.
• Treat SIP traces as sensitive. The baresip.native.sip trace contains call metadata for every party that contacts you and the digest material from authentication exchanges (see docs/LOGGING.md).

Passwords are never written to logs, traces, or repr() output by this library. Rate and concurrency limits (the max_concurrent_calls setting is reserved for this) and policy controls for call transfer are planned; until then, admission control lives in your on_incoming callback.