CVE-2026-18257

A heap-based out-of-bounds write vulnerability exists in S2OPC 1.7.3 in server-side EventFilter handling during CreateMonitoredItems processing. This allows a remote attacker to execute arbitrary code.

S2OPC through 1.7.3 contains a null pointer dereference in msg_subscription_publish_bs__alloc_notification_message_items() where a failed allocation for DataChangeNotification is overwritten by a successful allocation for EventNotificationList. Attackers can trigger heap allocation failures on sessions with both data-change and event notifications to cause the server process to terminate.

A vulnerability was identified in Systerel S2OPC up to 1.7.3. The function monitored_item_event_filter_treatment_bs__init_event_filter_ctx_and_result in subscription_mgr.c is vulnerable to use after free via the EventFilter argument. The attack may be performed remotely, and the exploit is public. A patch is available.

A vulnerability was determined in Systerel S2OPC up to 1.7.3 in the function set_range_matrix_on_string_array of src/Common/opcua_types/sopc_builtintypes.c in the String Array Range Writing component. This manipulation causes out-of-bounds read. The attack can be carried out remotely. The project was informed but has not responded.

A vulnerability has been found in Systerel S2OPC up to 1.7.3. Impacted is the function SOPC_NodeMgtHelperInternal_AddVariableNodeAttributes of the file src/ClientServer/address_space/internal/sopc_node_mgt_helper_internal.c of the component AddNodes Service. The manipulation of the argument UserAccessLevel leads to out-of-bounds read. It is possible to initiate the attack remotely. A high degree of complexity is needed for the attack. The exploitability is considered difficult. The exploit has been disclosed to the public and may be used. The identifier of the patch is aafbd37d381b618312ebdf5ddf57027f62c14fdd. It is suggested to install a patch to address this issue.

An issue in Systerel S2OPC 1.7.3 allows a remote attacker to cause a denial of service via the event monitored-item queue resize handling.

Buffer Overflow vulnerability in Systerel S2OPC 1.7.3 allows a remote attacker to cause a denial of service via the AddNodes, address_space_bs.c, sopc_node_mgt_helper_internal.c, and toolkit_test_server.

A buffer overflow vulnerability in Systerel S2OPC 1.7.3 allows a remote attacker to cause a denial of service via the Alarm/Conditions wrapper when processing PublishResponse EventNotificationList data.

A buffer overflow vulnerability in Systerel S2OPC 1.7.3 allows a remote attacker to cause a denial of service via the LockedStaMac_ProcessMsg_DeleteMonitoredItemsResponse and SOPC_StaMac_NewDeleteMonitoredItems functions in the client wrapper DeleteMonitoredItems path.

S2OPC 1.7.3 contains an out-of-bounds read in RepublishResponse handling, allowing a remote attacker to cause a denial of service.