CVE-2026-1301

Out-of-bounds Write in o6 Automation GmbH Open62541

MEDIUM

6.8

CVSS Score

Published: February 5, 2026 at 07:09 PM UTC

Updated: June 17, 2026 at 10:15 AM UTC

1 product affected across 1 vendorOpen62541

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Severity

MEDIUM6.8

Exploit prediction

EPSS 0.4%

SSVC

No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Open62541 · O6-automation

60%

1.5-rc1 ≤ v < 1.5-rc21.5-rc1

Affected range stops below 1.5-rc2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

US Government Resource

Source: [email protected]

https://www.cisa.gov/news-events/ics-advisories/icsa-26-036-03

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.8MEDIUMicscert

Vector?

Quick Info

StatusDEFERRED

CWE

CWE-787

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