CVE-2026-65423: o6 Automation open62541 · Integer Overflow
Affects o6 Automation open62541Source CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 29 Oct 2026, 07:15 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 56% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| o6 Automationopen62541 | 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 an official fix is available, users should consider restricting network access to the affected open62541 instances and monitor for unusual behavior. Avoid deploying affected versions in untrusted environments.
Description
An integer overflow in the UA_Variant arrayDimensions product computation in open62541 may allow a remote attacker to trigger an out-of-bounds write.
References
- o6-automation.com/contact (opens in a new tab)
- github.com/open62541/open62541/pull/8235/commits/b666d35769ce63998442e4d0810a3fb10b50179f (opens in a new tab)
- github.com/open62541/open62541/pull/8236/commits/06b99fef667c8ec5bdf0605b4f00c84fcc1d3a60 (opens in a new tab)
- github.com/open62541/open62541/pull/8237/commits/1b71d9c5d9c4d02d4729b8903a52e9f530bf804e (opens in a new tab)
- github.com/open62541/open62541/pull/8238/commits/afab4107bfd161da9ce8bb30ed77f3968c9c97df (opens in a new tab)
- cisa.gov/news-events/ics-advisories/icsa-26-211-08 (opens in a new tab)
- github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-08.json (opens in a new tab)