The security of our products is important to us as your industrial automation supplier. This security issue was found internally during routine testing and is being reported based on our commitment to customer transparency and improvement of all business environments.
Product Description
RSLinx® Classic from Rockwell Automation is a communications software that provides connectivity between Allen‑Bradley devices and Rockwell Automation applications, running as a Windows service to deliver real‑time data access for configuration, programming, and monitoring across industrial automation systems.
Affected Products and Solution
Affected Product |
CVE |
Affected Software Version |
Corrected in Software Version |
Affected Catalog Numbers |
RSLinx® Classic |
CVE-2026-9621 |
V4.50 and prior |
V4.60 |
9355-WAB****** |
RSLinx® Classic
|
CVE-2026-9622 |
V4.50 and prior
|
V4.60 |
9355-WAB****** |
RSLinx® Classic
|
CVE-2026-9624 |
V4.50 and prior
|
V4.60 |
9355-WAB****** |
RSLinx® Classic
|
CVE-2026-9625 |
V4.50 and prior
|
V4.60 |
9355-WAB****** |
Security Issue Details for CVE-2026-9621
Category |
Details |
CVE ID |
CVE-2026-9621 |
Impact |
A denial-of-service security issue exists within RSLinx® Classic. The security issue stems from improper handling of a malformed packet. A crafted CIP packet can cause the RSLinx® Classic service to crash, requiring a restart of the service to recover. |
CVSS 3.1 Base Score |
|
CVSS 4.0 Base Score |
|
CWE |
|
Known Exploited Vulnerability |
No |
Security Issue Details for CVE-2026-9622
Category |
Details |
CVE ID |
CVE-2026-9622 |
Impact |
A denial-of-service security issue exists within RSLinx® Classic. A crafted CIP packet targeting the Forward Close service can cause the RSLinx® Classic service to crash, requiring a restart of the service to recover. |
CVSS 3.1 Base Score |
|
CVSS 4.0 Base Score |
|
CWE |
|
Known Exploited Vulnerability |
No |
Security Issue Details for CVE-2026-9624
Category |
Details |
CVE ID |
CVE-2026-9624 |
Impact |
A denial-of-service security issue exists within RSLinx® Classic. A crafted CIP packet can cause the RSLinx® Classic service to crash due to insufficient data length validation, requiring a restart of the service to recover. |
CVSS 3.1 Base Score |
|
CVSS 4.0 Base Score |
|
CWE |
|
Known Exploited Vulnerability |
No |
Security Issue Details for CVE-2026-9625
Category |
Details |
CVE ID |
CVE-2026-9625 |
Impact |
A denial-of-service security issue exists within RSLinx® Classic. A crafted CIP packet with an oversized embedded message request can cause the RSLinx® Classic service to crash, requiring a restart of the service to recover. |
CVSS 3.1 Base Score |
|
CVSS 4.0 Base Score |
|
CWE |
CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
Known Exploited Vulnerability |
No |
Mitigations and Workarounds
Customers using the affected software, who are not able to upgrade to one of the corrected versions, should use our security best practices.
Revision History
Revision |
Date |
Description |
1.0 |
9/1/2026 |
Initial release |
Glossary:
· CIP: Common Industrial Protocol (CIP) is a common communication standard that is widely used in industrial automation. Comprises a series of protocols for communication between different devices and systems in automation technology
· CIP Packet: A data structure used in the Common Industrial Protocol (CIP) to encapsulate information for communication between industrial devices, including commands, responses, and associated parameters for control and data exchange
· Denial of Service (DoS): A malicious attempt to disrupt the normal functioning of a targeted server, service, or network by overwhelming it with a flood of traffic or triggering a crash.
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Support
If you have any questions regarding the security issue(s) above and how to mitigate them, contact TechConnect for help. More information can be found at Contact Us | Rockwell Automation | US.
If you have any questions regarding this disclosure, please contact PSIRT
Email: rasecure@ra.rockwell.com
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