CVE-2026-67859: open62541 · Classic Buffer Overflow
Affects open62541Source CVE Database V5
Not known to be exploited · CVSS 7.5 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.8% chance of exploitation in 30 days – higher than 57% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AC:L/AV:N/A:H/C:N/I:N/PR:N/S:U/UI:NExploitation evidence
Disclosed: evidence found.
CVE published 4 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubopen62541/open62541pkg:github/open62541/open62541Other threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, consider limiting exposure of the affected service and monitoring for unusual activity related to Discovery/LDS handling.
Description
A buffer overflow vulnerability exists in open62541 version 1.5.5 that allows a remote attacker to cause a denial of service via the Discovery/LDS handling functionality. This vulnerability has a high severity with a CVSS score of 7.5. No official patch or remediation has been confirmed at this time.
References
- github.com/open62541/open62541/blob/master/src/server/ua_services_discovery.c (opens in a new tab)
- github.com/open62541/open62541/blob/master/src/server/ua_discovery_mdns.c (opens in a new tab)
- github.com/open62541/open62541/issues/8095 (opens in a new tab)
- github.com/open62541/open62541/blob/master/examples/discovery/server_lds.c (opens in a new tab)
- github.com/open62541/open62541/blob/master/src/util/ua_util.c (opens in a new tab)