CVE-2026-67858: open62541 · Classic Buffer Overflow
Source 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 58% 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
AI-suggested
Until a fix is available, consider disabling multicast discovery or restricting access to the Local Discovery Server to trusted networks to reduce exposure.
Description
A buffer overflow vulnerability exists in open62541 version 1.5.5 when the Local Discovery Server (LDS) is configured with multicast discovery enabled via the MDNSD backend. An unauthenticated remote attacker can exploit this by sending a RegisterServer or RegisterServer2 request with many unique discoveryUrls, leading to a denial of service condition.
References
- github.com/open62541/open62541/issues/8094 (opens in a new tab)
- github.com/open62541/open62541/tree/master/examples/discovery (opens in a new tab)
- 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/blob/master/doc/building.rst (opens in a new tab)