In open62541 v1.5.5, the server-side AddReferences implementation contains an incomplete validation flaw for non-local ExpandedNodeId targe…

published 2026-08-05 3 mo ago modified 2026-08-31 2 mo ago also EUVD-2026-53681

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 64%
public exploits: 0; none known

In open62541 v1.5.5, the server-side AddReferences implementation contains an incomplete validation flaw for non-local ExpandedNodeId targets. A remote attacker can send a crafted AddReferencesRequest with an empty targetServerUri and a non-zero targetNodeId.serverIndex, causing the target node pointer to remain NULL while execution continues.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-67870 updated 2026-08-06 cvss 7.5

open62541: open62541: Denial of Service via incomplete validation in AddReferences

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 3 mo ago (2026-08-06)

Exploit prediction

1.06% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/open62541/open62541/issues/8172 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

Weakness

CWE-476 NULL Pointer Dereference

References

Sources

CVE List CVE-2026-67870
NVD CVE-2026-67870

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary