Buffer overflow in O6 Open62541
CVE-2026-18784
A vulnerability was found in o6 open62541 up to 1.5.5. This issue affects the function UA_Client_readNodeClassAttribute of the file src/client/ua_client_highlevel.c. Performing a manipulation results in heap-based buffer overflow. Attacking locally is a requirement. The exploit has been made public and could be used. The project closed the issue report, stating that this is not the official way to report a security vulnerability.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (6.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- O6 Open62541 — versions 1.5.0, 1.5.1, 1.5.2
Weakness classification (CWE)
References
- github.com/gff-cw/information/issues/11 (issue-tracking, exploit)
- github.com/open62541/open62541/issues/8139 (issue-tracking)
- vuldb.com/cve/CVE-2026-18784 (third-party-advisory)
- vuldb.com/submit/857012 (third-party-advisory)
- vuldb.com/vuln/385786 (technical-description, vdb-entry)
- vuldb.com/vuln/385786/cti (signature, permissions-required)
Frequently asked questions
- What is CVE-2026-18784?
- CVE-2026-18784 is a medium-severity vulnerability in O6 Open62541, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2026-08-04.
- How severe is CVE-2026-18784?
- Medium severity. CVSS v3 base score is 5.3 out of 10.