# CVE-2026-65423 — o6 Automation open62541

> As of 2026-07-31, CVE-2026-65423 is a HIGH-severity vulnerability in o6 Automation open62541, CVSS v3.1 8.8, EPSS 0.6% (45.5th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-65423 as of 2026-07-31; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-31

## What is CVE-2026-65423?

An integer overflow in the UA_Variant arrayDimensions product computation in open62541 may allow a remote attacker to trigger an out-of-bounds write.

The record classifies CVE-2026-65423 under weakness class [CWE-190](https://intel.threadlinqs.com/cwe/CWE-190). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 67 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 8.8 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **CVSS v4.0 base score:** 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **EPSS (FIRST):** 0.6% probability of exploitation in the next 30 days, higher than 45.5% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-30, last modified 2026-07-31

## Is CVE-2026-65423 being exploited?

It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **o6 Automation**: open62541

## How to fix CVE-2026-65423

No vendor patch reference has been recorded for CVE-2026-65423 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-65423

No threat campaign in the Threadlinqs corpus currently references CVE-2026-65423, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-08-03. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [o6-automation.com](https://www.o6-automation.com/contact)
- [github.com](https://github.com/open62541/open62541/pull/8235/commits/b666d35769ce63998442e4d0810a3fb10b50179f)
- [github.com (06b99fef667c8ec5bdf0605b4f00c84fcc1d3a60)](https://github.com/open62541/open62541/pull/8236/commits/06b99fef667c8ec5bdf0605b4f00c84fcc1d3a60)
- [github.com (1b71d9c5d9c4d02d4729b8903a52e9f530bf804e)](https://github.com/open62541/open62541/pull/8237/commits/1b71d9c5d9c4d02d4729b8903a52e9f530bf804e)
- [github.com (afab4107bfd161da9ce8bb30ed77f3968c9c97df)](https://github.com/open62541/open62541/pull/8238/commits/afab4107bfd161da9ce8bb30ed77f3968c9c97df)

_Showing 5 of 7 recorded references._

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-65423
Full detection coverage and IOCs for threats exploiting CVE-2026-65423 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp