# CVE-2026-67862

> As of 2026-08-05, CVE-2026-67862 is a HIGH-severity vulnerability, CVSS v3.1 7.5, EPSS 0.2% (11.4th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-67862 as of 2026-08-05; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-05

## What is CVE-2026-67862?

open62541 1.5.5 contains a buffer-overflow in the high-level attribute reading logic in src/client/ua_client_highlevel.c. This allows a remote attacker to cause a denial of service.

The record classifies CVE-2026-67862 under weakness class [CWE-400](https://intel.threadlinqs.com/cwe/CWE-400). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. The identifier was first published 62 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.2% probability of exploitation in the next 30 days, higher than 11.4% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-04, last modified 2026-08-05

## Is CVE-2026-67862 being exploited?

It currently carries a trending score of 32 in the Threadlinqs vulnerability feed.

## Affected products and versions

No affected-product or package list has been recorded for CVE-2026-67862 in the tracked sources. The vendor advisory and the references below are the authoritative statement of what is affected.

## How to fix CVE-2026-67862

No vendor patch reference has been recorded for CVE-2026-67862 in the tracked sources. Follow the references below for a fix, and treat any affected deployment as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-67862

No threat campaign in the Threadlinqs corpus currently references CVE-2026-67862, 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 2026-08-06. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [github.com](https://github.com/open62541/open62541/issues/8139)
- [github.com (ua client highlevel)](https://github.com/open62541/open62541/blob/v1.5.5/src/client/ua_client_highlevel.c)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-67862
Full detection coverage and IOCs for threats exploiting CVE-2026-67862 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp