CVE-2026-67858 Details
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.
A buffer overflow vulnerability has been identified in open62541 version 1.5.5. This issue arises when the Local Discovery Server (LDS) is configured to use multicast discovery via the MDNSD backend. An unauthenticated remote attacker can exploit this vulnerability by sending a RegisterServer or RegisterServer2 request that includes a large number of unique discovery URLs. This exploitation leads to a denial-of-service condition by causing the server to crash.
Users can disable multicast discovery or avoid using the open62541 Local Discovery Server example to mitigate this vulnerability. However, a proper patch should be applied once available.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Aug 4, 2026CISA-ADP
Assessed Aug 5, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/open62541/open62541/issues/8094 | CISA-ADP | ExploitIssue TrackingTechnical DescriptionVendor |
| https://github.com/open62541/open62541/blob/master/doc/building.rst | [email protected] | Source CodeVendor |
| https://github.com/open62541/open62541/blob/master/src/server/ua_discovery_mdns.c | [email protected] | Broken LinkSource CodeVendor |
| https://github.com/open62541/open62541/blob/master/src/server/ua_services_discovery.c | [email protected] | Source CodeVendor |
| https://github.com/open62541/open62541/issues/8094 | [email protected] | ExploitIssue TrackingTechnical DescriptionVendor |
| https://github.com/open62541/open62541/tree/master/examples/discovery | [email protected] | Vendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| open62541 | 1.5.5 (semver) |
CPE
Remediation
| |
| open62541 Local Discovery Server | All versions |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 5, 2026 | CVE Modified | CISA-ADP |
| Aug 4, 2026 | New CVE Received | [email protected] |