S2OPC 1.7.3 release

The S2OPC team is proud to announce the 1.7.3 release of S2OPC.

This is mainly a security release. It fixes two vulnerabilities related to certificate trust and revocation checking, and we strongly recommend all users to upgrade. It also brings a new feature completing the Cyclone library wrapper, along with several enhancements and bug fixes.

Security

This release fixes the two following vulnerabilities:

  • CVE-2026-9758 (see ticket #1770): Improper comparison with the certificates trusted list in S2OPC allows a well-formed untrusted certificate to be considered trusted.
  • CVE-2026-6899 (see ticket #1739), when using the CycloneCrypto wrapper only: the certificate revocation check only considers the first matching CRL and ignores other valid CRLs of the same CA in the CycloneCrypto cryptographic wrapper. It might allow a connection between an OPC UA client and server using a revoked certificate.

New features

  • Ticket #1738: Implement missing functions in the Cyclone library wrapper

Enhancements

Some notable enhancements are:

  • Ticket #1690: File Transfer Rework continuation
  • Ticket #1733: Migrate to cyclone crypto 2.6.0 (compatible >=2.52)
  • Ticket #1746: AddressSpaceAccess_WriteValue: inhibits write of Timestamp/StatusCode when const address space is used
  • Ticket #1750: Completely fill OpcUa_ReferenceDescription in SOPC_AddressSpaceAccess_BrowseNode

Bug fixed and known bugs

The list of fixed bugs and of known bugs is available in the 1.7.3 Gitlab release page.

What is S2OPC ?

S2OPC is a software solution for client-server and pub-sub communications using OPC UA standard.

  • designed to target the cyber-security and real-time constraints of embedded products
  • deployed on larger command-control or supervision systems

S2OPC has a security visa from ANSSI for the CSPN certification and a certificate of compliance with the OPC UA v1.04 standard from the OPC Foundation.

Multiplatform SDK, S2OPC is used in application scaling from IIoT modules to SCADA systems. It supports both Client/Server and PubSub. S2OPC is also ready for integration with TSN networks.

S2OPC is an open-source solution for OPC UA communications.