OpenSIPS 4.0.1 ChangeLog

Released on August 19, 2026

OpenSIPS 4.0.1 is the first maintenance release for the 4.0 stable branch, collecting fixes and improvements since 4.0.0. The release includes networking and TCP fixes, parser/input hardening, dialog and B2B stability work, TLS policy fixes, OpenTelemetry updates and a large documentation and CI refresh.

This changelog summarizes the user-visible changes from 4.0.0..4.0.1. The range contains 134 non-merge commits; generated documentation churn and release mechanics are summarized rather than listed verbatim.

Network and Core Fixes

  • Fixed TCP dispatch handling for NULL messages. 1ddabc36cc
  • Ensured TCP connection IDs are unique. cb640e5e88
  • Fixed a TCP connection reference leak in tcp_async_write_job(). b9669fd2dd
  • Fixed a sockets_mgm race in receive_fd() which could cause an infinite loop during reload. 92e0f82ff4
  • Added standalone M4 configuration examples and refreshed default configuration material. 07326af4f6

Input Hardening and Parser Safety

  • Handled empty multipart bodies in the SIP message translator. 79d681671a
  • Rejected overlong PUA publish ETags. e7950dd884
  • Bounded SDP connection-line insertion in mediaproxy. 72e9c4325e
  • Rejected overlong ISN R-URI users in enum. d7db34cc38
  • Rejected overlong SIP URI normalization input in xcap. eea545e97d

Dialog, B2B and Media Handling

  • Fixed SIPREC dialog callback reference ownership. f43752ea5d
  • Matched dialog legs by transaction branch, improving reply-leg association. 4e662fa87f
  • Fixed a b2b_logic lock leak and self-deadlock. 0050444fd9
  • Added dialog reference counting to b2b_entities and related b2b_sdp_demux paths. b8b7fa5e8b
  • Fixed possible invalid dialog access in b2b_entities and cross-BYE concurrency in b2b_sdp_demux. b318221c04 88009791c3
  • Properly populated rtp_relay leg tags during parallel forking. fa501f9ddc

Module Fixes

  • Fixed AoR replication with populated kv_storage in mid_registrar/usrloc. a8780f2bf6
  • Fixed cgrates unref handling on error and concurrent BYE, and restored accounting context during dialog variable replication. 2a4949cb27 ceaf78aab0
  • Fixed anycast replication return codes and added context for replicated CANCEL handling in tm. 4855d86e43 cc9ba55fb0
  • Simplified gflags MI commands. 53f58106ab
  • Fixed UUID v7 compilation on older systems. bf45a295f6
  • Fixed MSRP relay optional authentication body initialization. 8d67fbc576
  • Added support for modern RabbitMQ headers in event_rabbitmq and rabbitmq_consumer while preserving legacy header compatibility. b66d169291 5467c5f90c

TLS and Security Modules

  • Unified TLS verify mode selection in tls_mgm. b9f88a2bf7
  • Fixed require_cert and verify_cert enforcement for TLS virtual domains. 7a7a0571b9
  • Fixed a STIR/SHAKEN PKG memory leak on non-ppt=shaken paths. 9792b48843
  • Fixed aaa_diameter cJSON ownership bugs, including a double-free in dm_avps2json() and reply cJSON release regardless of output PV handling. d6543cc31f f8cc1da014

Observability and OpenTelemetry

  • Handled process profiling events in OpenTelemetry. 18459029ac
  • Fixed C++ object build cleanup in OpenTelemetry. fc1b2c3c17
  • Enabled OpenTelemetry checks on Ubuntu 26.04 and installed the needed dependencies in CI. 8796b30acc 4e526a1e83

Build, CI, Packaging and Documentation