CVE-2026-67860 is a heap-based buffer overflow vulnerability in open62541 version 1.5.5. It occurs in the default HistoryRead path when the default history database is used with the memory backend. The flaw can cause a crash of the application, resulting in denial of service. The vulnerability is categorized under CWE-122 (Heap-based Buffer Overflow). No official remediation or patch has been documented at this time.

The vulnerability allows an attacker to cause a denial of service by triggering a heap-based buffer overflow in the affected component. There is no indication of confidentiality or integrity impact. No known exploits are reported in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should consider avoiding use of the default HistoryRead path with the memory backend or apply any recommended workarounds from the vendor once published.