CVE-2026-67858

high

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/tree/master/examples/discovery

https://github.com/open62541/open62541/issues/8094

https://github.com/open62541/open62541/blob/master/src/server/ua_services_discovery.c

https://github.com/open62541/open62541/blob/master/src/server/ua_discovery_mdns.c

https://github.com/open62541/open62541/blob/master/doc/building.rst

Details

Source: Mitre, NVD

Published: 2026-08-04

Updated: 2026-08-04

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High