Vulnerability · Published Jul 14, 2026 · Assigned by Rockwell
CVE-2026-9636Rockwell Automation CompactLogix® 5380 ControlLogix® 5580 / 1756-EN4 Communications Module – Certificate Revocation List Vulnerability
High 8.2
In plain English
A high-severity security flaw in ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TR from Rockwell Automation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).
Official description
A security issue exists within CompactLogix® 5380, ControlLogix® 5580, and EN4 communication modules related to CIP Security certificate revocation handling. The security issue stems from the controller failing to properly reject certificates signed by an intermediate certificate that has been revoked via a Certificate Revocation List (CRL). This could allow a network-based attacker to establish a connection using a certificate that should be untrusted, potentially bypassing CIP Security protections.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Rockwell Automation | ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TR | Version 36 - Version 37 |
Weakness: CWE-299 · Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N