CVE-2026-67861 open62541 CVE debrief

Who should care

Organizations using open62541 v.1.5.5 and before should be aware of this vulnerability and take steps to mitigate it. This includes reviewing their deployments for potential exposure, applying patches or updates, and monitoring for potential denial of service attacks. Security teams and vulnerability management teams should prioritize this vulnerability and ensure that affected systems are patched or mitigated promptly. Additionally, operators and administrators of open62541 deployments should be aware of the potential impact of this vulnerability on their systems and take steps to minimize the risk of exploitation.

Technical summary

A denial of service vulnerability exists in open62541 v.1.5.5 and before via the UA_Client_getRemoteDataTypes component. An attacker can exploit this vulnerability to cause a denial of service. The vulnerability is related to the handling of remote data types, which could lead to a crash or unexpected behavior. Organizations using open62541 should review their deployments and consider applying patches or updates to mitigate this vulnerability.

Defensive priority

Organizations using open62541 v.1.5.5 and before should prioritize patching to prevent potential denial of service attacks.

Recommended defensive actions

• Apply patches or updates for open62541 v.1.5.5 and before
• Restrict access to the UA_Client_getRemoteDataTypes component
• Monitor for potential denial of service attacks
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record indicates a denial of service vulnerability in open62541 v.1.5.5 and before via the UA_Client_getRemoteDataTypes component. Evidence is limited, and further verification is needed to determine the full scope of the vulnerability. The vulnerability affects open62541 versions prior to 1.5.6, and defenders should verify their deployments for potential exposure. Additional review of the UA_Client_getRemoteDataTypes component is required to understand the vulnerability's impact fully.

Official resources