8.2
HIGH CVSS 4.0
CVE-2026-9636
Rockwell Automation CompactLogix® 5380 ControlLogix® 5580 / 1756-EN4 Communications Module – Certificate Revocation List Vulnerability
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issue stems from the controller failing to properly reject certificates signed by an intermediate certificate that has been revoked via a Certificate Revocation List (CRL).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.

INFO

Published Date :

July 14, 2026, 4:17 p.m.

Last Modified :

July 14, 2026, 4:46 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-9636 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 HIGH b73dd486-f505-4403-b634-40b078b177f0
CVSS 4.0 HIGH [email protected]
Solution
Update firmware to correctly handle revoked certificates and enforce CIP Security.
  • Update controller firmware to the latest version.
  • Apply security patches for affected modules.
  • Verify CIP Security configurations are enforced.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-9636.

URL Resource
https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1788.html
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-9636 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-9636 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-9636 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-9636 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 14, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Rockwell Automation', 'product': 'ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TR', 'versions': [{'status': 'affected', 'version': 'Version 36 - Version 37'}], 'defaultStatus': 'unaffected'}]
    Added 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.
    Added CVSS V4.0 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
    Added CWE CWE-299
    Added Reference https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1788.html
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 14, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-9636', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-14T15:54:57.625184Z'}
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.