CVE-2026-9636

HIGHCVSS 8.2/10

Last modified

CVE-2026-9636 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. 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issue stems from the controller failing to properly reject certificates signed by an intermediate certificate that has been revoked via a Certificate Revocation List (CRL).

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issue stems from the controller failing to properly reject certificates signed by an intermediate certificate that has been revoked via a Certificate Revocation List (CRL).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.

Metrics

CVSS 4.0
8.2/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Rockwell AutomationControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TRVersion 36 - Version 37

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-9636?
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issue stems from the controller failing to properly reject certificates signed by an intermediate certificate that has been revoked via a Certificate Revocation List (CRL).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.
How severe is CVE-2026-9636?
CVE-2026-9636 has a CVSS score of 8.2/10 (HIGH severity).
How do I fix CVE-2026-9636?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-9636?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST