CVE-2026-67858
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
0.9%
56.6th percentile
CISA KEV
Not listed
Weakness / dates
CWE-120
Published 2026-08-04 · modified 2026-08-31
Description
Buffer Overflow vulnerability exists in open62541 1.5.5 when the Local Discovery Server (LDS) is built with multicast discovery enabled through the MDNSD backend. An unauthenticated remote attacker can send a RegisterServer or RegisterServer2 request containing many unique discoveryUrls. This allows remote attackers to cause a denial of service.
References
- https://github.com/open62541/open62541/blob/master/doc/building.rst
- https://github.com/open62541/open62541/blob/master/src/server/ua_discovery_mdns.c
- https://github.com/open62541/open62541/blob/master/src/server/ua_services_discovery.c
- https://github.com/open62541/open62541/issues/8094
- https://github.com/open62541/open62541/tree/master/examples/discovery
- https://github.com/open62541/open62541/issues/8094