Buffer overflow in O6 Automation Gmbh Open62541

CVE-2026-1301

In builds with PubSub and JSON enabled, a crafted JSON message can cause the decoder to write beyond a heap-allocated array before authentication, reliably crashing the process and corrupting memory.

Vulnerability class: Buffer Overflow

EPSS: 0.003 (26.9th percentile) — read the EPSS interpretation.