CVE-2026-0646 Rockwell Automation FLEX I/O Dual-port EtherNet/IP Adapters – Multiple Vulnerabilities
Attackers can cause a denial of service in Rockwell FLEX I/O adapters by sending malformed CIP requests, requiring manual reset to recover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-0646?
CVE-2026-0646 is a high-severity denial of service vulnerability in Rockwell Automation FLEX I/O EtherNet/IP Adapters, published on 16 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A denial-of-service security issue exists within the 1794-AENTR adapter due to improper memory handling of CIP protocol requests. This vulnerability can result in the adapter faulting and losing connection to its associated I/O modules, requiring a manual reset to recover.
Weakness: CWE-401
Which versions are affected by CVE-2026-0646?
How do I fix CVE-2026-0646?
No fix has been published for CVE-2026-0646 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-0646 being exploited?
There is no known exploitation of CVE-2026-0646 in the wild and no public exploit code.
Sources
Also known as GHSA-42rg-42xm-fx4v.