Vulnerability · Published Feb 5, 2026 · Assigned by icscert
CVE-2026-1301Out-of-bounds Write in o6 Automation GmbH Open62541
Medium 6.8
In plain English
A medium-severity out-of-bounds write in Open62541 from o6 Automation GmbH. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities).
Severity (CVSS 4.0)6.8Medium
Exploit odds (30 days)0.4%top 67.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
In builds with PubSub and JSON enabled, a crafted JSON message can cause the decoder to write beyond a heap-allocated array before authentication, reliably crashing the process and corrupting memory.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| o6 Automation GmbH | Open62541 | 1.5-rc1 – before 1.5-rc2 |
Weakness: CWE-787 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-036-03 government-resource