CVE-2026-67870: In open62541 v1.5.5, the server-side AddReferences implementation contains an incomplete validation flaw for n

This month

CRITICAL 9.8REMOTE

CVE-2026-67870 is a critical-severity flaw (CVSS 9.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
CISA SSVC: public proof of concept
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 36%)
CISA exploited list	No
Weakness	CWE-476
Published	2026-08-06
Last modified	2026-08-31

Publisher (CNA): MITRE

Last updated 2026-08-31 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-06 00:16 UTCPublished CVE record published
2026-08-31 19:33 UTCUpdated Record last modified

Exact fixes by distribution

Fedora ELN · gram_grep · FIXED · 0.10.3-2.eln159 · FEDORA-2026-29427819d0 · source

sudo dnf upgrade --advisory=FEDORA-2026-29427819d0

Fedora 46 · python3.11 · FIXED · 3.11.18-1.fc46 · FEDORA-2026-cc775894f4 · source

sudo dnf upgrade --advisory=FEDORA-2026-cc775894f4

Debian 13 · open62541 · NO FIX YET

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/open62541/open62541/issues/8172

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-67870?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-67870 being exploited?

CVE-2026-67870 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-67870 affect?

CVE-2026-67870 affects affected software. Severity is critical (CVSS 9.8). 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

How urgent is CVE-2026-67870?

Priority 58/100. Critical severity; CISA SSVC: public proof of concept; Remotely exploitable, no login, no user action

References

← Back to latest CVEs