Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-08-05T00:00:00 open62541: open62541: Denial of Service via incomplete validation in AddReferences 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-476

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.

A flaw was found in open62541. A remote attacker can exploit an incomplete validation flaw in the server-side AddReferences implementation. By sending a specially crafted request, an attacker can cause a null pointer dereference, leading to a Denial of Service (DoS) condition. This can make the server unavailable to legitimate users.

This Important denial of service flaw in open62541 allows a remote, unauthenticated attacker to crash the server. The vulnerability arises from insufficient validation of non-local ExpandedNodeId targets within the AddReferences implementation, which can lead to a NULL pointer dereference and service unavailability. Restrict who can invoke NodeManagement / AddReferences (trusted clients only) and limit OPC UA server network exposure. https://www.cve.org/CVERecord?id=CVE-2026-67870 https://nvd.nist.gov/vuln/detail/CVE-2026-67870 https://github.com/open62541/open62541/blob/v1.5.5/include/open62541/types.h https://github.com/open62541/open62541/blob/v1.5.5/src/server/ua_services_nodemanagement.c https://github.com/open62541/open62541/blob/v1.5.5/src/ua_types.c https://github.com/open62541/open62541/issues/8172