OTPulse

RSLinx Classic Third-Party Vulnerability

MonitorCVSS 7.5ICS-CERT ICSA-26-167-02Jun 16, 2026
Rockwell Automation
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary

RSLinx Classic version 4.50.00 and earlier contain a vulnerability that causes denial of service. Successful exploitation results in the application becoming unresponsive and not recovering automatically. The vulnerability requires no authentication and can be triggered remotely.

What this means
What could happen
An attacker can crash RSLinx Classic, making it unresponsive and preventing operators from monitoring or controlling connected devices until the application is manually restarted.
Who's at risk
Operators and engineers using Rockwell Automation's RSLinx Classic software for monitoring and controlling Allen-Bradley PLCs, drives, and other devices in manufacturing, water treatment, electric utility, and other industrial environments should apply this update.
How it could be exploited
An attacker with network access to RSLinx Classic sends a specially crafted request to the application. The vulnerability causes the application to crash and become unresponsive, requiring manual restart to restore functionality.
Prerequisites
  • Network access to RSLinx Classic
  • No authentication required
  • RSLinx Classic version 4.50.00 or earlier
remotely exploitableno authentication requiredlow complexityaffects process visibility and control
Exploitability
Some exploitation risk — EPSS score 3.4%
Affected products (1)
ProductAffected VersionsFix Status
RSLinx Classic≤ 4.50.00No fix yet
Remediation & Mitigation
0/4
Do now
0/1
WORKAROUNDRestrict network access to RSLinx Classic to only authorized engineering and operator workstations using firewall rules
Schedule — requires maintenance window
0/2

Patching may require device reboot — plan for process interruption

HOTFIXUpgrade RSLinx Classic to version 4.60.00 or later
HOTFIXIf unable to upgrade immediately, apply patch BF31213 to your current RSLinx Classic version
Long-term hardening
0/1
HARDENINGImplement network segmentation to isolate RSLinx Classic and connected devices on a separate OT network from untrusted networks
View full CISA ICS-CERT advisory
API: /api/v1/advisories/6d6d128f-942b-4492-beef-6ce039837859

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