CVE-2026-67856 Denial of service in n/a
Remote attackers can cause denial of service in open62541 by sending crafted OPC UA subscription and monitoring requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-67856?
CVE-2026-67856 is a high-severity denial of service vulnerability in n/a, published on 4 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue in open62541 v.1.5.5 and before allows a remote attacker to cause a denial of service via crafted CreateSubscription, CreateMonitoredItems(Sampling), Publish, TransferSubscriptions, and DeleteSubscriptions requests
Weakness: CWE-400
Which versions are affected by CVE-2026-67856?
How do I fix CVE-2026-67856?
No fix has been published for CVE-2026-67856 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-67856 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67856 exists.
Sources
Also known as DEBIAN-CVE-2026-67856, GHSA-xph2-98f4-p64h, UBUNTU-CVE-2026-67856.