CVE-2026-9653 1756-EN2, 1756-EN3, and 1756-ENBT - Denial of Service via CIP Connection ID
An attacker can cause temporary denial of service on Rockwell industrial communication modules by sending crafted CIP packets.
- 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-2026-9653?
CVE-2026-9653 is a high-severity denial of service vulnerability in Rockwell Automation 1756-EN2, 1756-EN3, published on 14 Jul 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 across all the 1756-EN2, EN3, and ENBT communication module due to improper validation of CIP Implicit Connection packets. An attacker on the network can exploit this by sending crafted packets to continuously disrupt device connections, though device connections will recover immediately after.
Weakness: CWE-354
Which versions are affected by CVE-2026-9653?
How do I fix CVE-2026-9653?
No fix has been published for CVE-2026-9653 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-2026-9653 being exploited?
There is no known exploitation of CVE-2026-9653 in the wild and no public exploit code.
Sources
Also known as GHSA-w8xr-7458-qr4m.