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Vulnerabilities

Vulnerability · CVE-2026-9636

Rockwell Automation CompactLogix® 5380 ControlLogix® 5580 / 1756-EN4 Communications Module – Certificate Revocation List Vulnerability

Published Jul 14, 2026 · catalog updated Jul 14, 2026 · Rockwell Automation ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TR

Open the advisory

Exploitation likelihood is not on this record for CVE-2026-9636. A missing EPSS score is not a low risk. Compare Rockwell Automation ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TR with the linked advisory before you change production.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
  • EPSS is missing. A missing score is not a low risk.
Severity
High8.2
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
Not in the current FIRST EPSS dataset
Remediation
Advisory link
Affected products
vendor Rockwell Automation ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TR

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issue stems from the controller failing to properly reject certificates signed by an intermediate certificate that has been revoked via a Certificate Revocation List (CRL).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

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Rockwell Automation ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TRversion unspecified

How to fix CVE-2026-9636

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

Exploitation likelihood is not on this record for CVE-2026-9636. A missing EPSS score is not a low risk. Compare Rockwell Automation ControlLogix® 5580, CompactLogix® 5380, GuardLogix® 5580, Compact GuardLogix® 5380, 1756-EN4TR with the linked advisory before you change production.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-299. EPSS is absent from the current FIRST dataset. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 14, 2026 · CIRCL Vulnerability Lookup

    Detected

    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

  2. Jul 14, 2026 · CIRCL Vulnerability Lookup

    Updated

    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

Sources

  • CIRCL Vulnerability LookupVulnerability recordCVE-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

    vulnerability.circl.lu
  • CVE.orgVulnerability recordCVE-2026-9636

    Official CVE identifier

    cve.org

References

Freshness

Last verified in this catalog Oct 24, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.