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

Published · last modified .

EPSS exploit prediction

EPSS: 0.004 (28.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-1301: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References