CVE-2026-67866
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk20th percentile - higher than 20% of all known CVEs
Summary
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.
Risk Assessment
A remote attacker could exploit this to disrupt OPC clients, potentially causing interruptions in industrial communication.
Recommendation
Update Systerel S2OPC to a patched version and monitor network traffic for suspicious DeleteMonitoredItems requests.
Other vulnerabilities in S2OPC
See all- CVE-2026-67868Critical
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.
- CVE-2026-78049Low
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.
- CVE-2026-67872High
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.
- CVE-2026-67871High
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.
- CVE-2026-67867High
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.
- CVE-2026-67865High
S2OPC 1.7.3 contains an out-of-bounds read in RepublishResponse handling, allowing a remote attacker to cause a denial of service.
- CVE-2026-18257Medium
Improper validity period check for the root issuer certificate in CycloneCrypto cryptographic wrapper of S2OPC allows a certificate issued by this root issuer to be considered trusted even if it is invalid.
- CVE-2026-9758High
Improper comparison with the trusted certificates list in S2OPC allows an attacker to have a well-formed untrusted certificate considered trusted.
- CVE-2026-6899Medium
The certificate revocation check in the CycloneCrypto cryptographic wrapper of the S2OPC library only considers the first matching CRL, ignoring other valid CRLs of the same CA. This could allow an OPC UA client and server to connect using a revoked certificate.
Original NVD description (English source)
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 in the client wrapper DeleteMonitoredItems path