Vulnerability · Published Aug 4, 2026 · Assigned by mitre
CVE-2026-67856
High 7.5
In plain English
A high-severity uncontrolled resource consumption in the open62541 package (Debian). Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 55% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.8%top 44.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
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
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | open62541 | no fix listed | DEBIAN-CVE-2026-67856 |
| Debian:14 | open62541 | no fix listed | DEBIAN-CVE-2026-67856 |
| Ubuntu:26.04:LTS | open62541 | no fix listed | UBUNTU-CVE-2026-67856 |
| Ubuntu:26.10 | open62541 | no fix listed | UBUNTU-CVE-2026-67856 |
Affected products (as reported)
Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/open62541/open62541/issues/8092
- https://github.com/open62541/open62541/blob/master/src/server/ua_services_subscription.c
- https://github.com/open62541/open62541/blob/master/src/server/ua_subscription.c
- https://github.com/open62541/open62541/blob/master/src/server/ua_subscription.h
- https://github.com/open62541/open62541/blob/master/examples/access_control/server_access_control.c