CVE-2026-18784
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
A vulnerability was found in o6 open62541 up to 1.5.5. This issue affects the function UA_Client_readNodeClassAttribute of the file src/client/ua_client_highlevel.c. Performing a manipulation results in heap-based buffer overflow. Attacking locally is a requirement. The exploit has been made public and could be used. The project closed the issue report, stating that this is not the official way to report a security vulnerability.
Risk Assessment
The risk includes potential arbitrary code execution or application crash due to a local attack, which could lead to privilege escalation or system integrity compromise.
Recommendation
Update open62541 to a version newer than 1.5.5 if available, and monitor official security channels of the project.
Other vulnerabilities in open62541
See all- CVE-2026-15690Low
A vulnerability was found in open62541 up to version 1.5.5, affecting the function responseReadNamespacesArray in src/client/ua_client_connect.c. Manipulation of the Server_NamespaceArray argument causes a null pointer dereference, potentially leading to application crashes. The attack can be executed remotely but requires high complexity and is difficult to exploit.
- CVE-2026-11946High
An unauthenticated remote attacker can exhaust server memory via the GetEndpoints Discovery Service in open62541. The endpointUrl field of GetEndpointsRequest is not validated for length, allowing an arbitrarily large string (up to ~4.09 GB) to be declared and delivered across intermediate chunks without ever sending the final chunk. The server buffers all chunks in RAM indefinitely until the SecureChannel times out.
- CVE-2026-67870Critical
In open62541 v1.5.5, the server-side AddReferences implementation contains an incomplete validation flaw for non-local ExpandedNodeId targets. A remote attacker can send a crafted AddReferencesRequest with an empty targetServerUri and a non-zero targetNodeId.serverIndex, causing the target node pointer to remain NULL while execution continues.
- CVE-2026-67869High
Buffer Overflow vulnerability in open62541 v1.5.5 allows a remote attacker to cause a denial of service via the Service_Call, which validates input arguments against runtime-resolved InputArguments metadata.
- CVE-2026-67863High
In open62541 1.5.5, a server-side use-after-free exists in the local MonitoredItem callback path. The issue occurs when UA_Subscription_localPublish continues to use the current UA_Notification after a callback invokes UA_Server_deleteMonitoredItem for the current local MonitoredItem. This allows a remote attacker to cause a denial of service.
- CVE-2026-67864High
An issue in open62541 v.1.5.5 and before allows a remote attacker to cause a denial of service via the NodeManagement type-instantiation logic component.
- CVE-2026-67862High
open62541 1.5.5 contains a buffer-overflow in the high-level attribute reading logic in src/client/ua_client_highlevel.c. This allows a remote attacker to cause a denial of service.
- CVE-2026-67861High
An issue in open62541 v.1.5.5 and before allows a remote attacker to cause a denial of service via the UA_Client_getRemoteDataTypes component.
- CVE-2026-67860High
open62541 version 1.5.5 contains a heap-based buffer overflow in the default HistoryRead path when the default history database is used with the memory backend.
- CVE-2026-67859High
Buffer overflow vulnerability in open62541 v1.5.5 allows a remote attacker to cause a denial of service via Discovery/LDS handling.
Original NVD description (English source)
A vulnerability was found in o6 open62541 up to 1.5.5. This issue affects the function UA_Client_readNodeClassAttribute of the file src/client/ua_client_highlevel.c. Performing a manipulation results in heap-based buffer overflow. Attacking locally is a requirement. The exploit has been made public and could be used. The project closed the issue report, stating that this is not the official way to report a security vulnerability.