What is CVE-2026-67863?
In open62541 1.5.5, a server-side use-after-free exists in the local MonitoredItem callback path. The issue occurs when UA_Subscription_localPublish continues to use the current UA_Notification after a callback invokes UA_Server_deleteMonitoredItem for the current local MonitoredItem. This allows a remote attacker to cause a denial of service.
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 61 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.5 — HIGH
CVSS:3.1/AC:L/AV:N/A:H/C:N/I:N/PR:N/S:U/UI:N - CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-08-05, last modified 2026-08-06
Is CVE-2026-67863 being exploited?
It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
Affected products and versions
No affected-product or package list has been recorded for CVE-2026-67863 in the tracked sources. The vendor advisory and the references below are the authoritative statement of what is affected.
How to fix CVE-2026-67863
No vendor patch reference has been recorded for CVE-2026-67863 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-2026-67863
No threat campaign in the Threadlinqs corpus currently references CVE-2026-67863, 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. Last verified by Threadlinqs on .