CVE-2026-9621 | BDVDB-2026-366755 Detail

Rockwell AutomationRSLinx Classic®

Description#

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

Impact#

Per CVSS v4.0: confidentiality impact none, integrity impact none, availability impact high. Attack vector: network.

Weaknesses#

CWE-190 Integer Overflow or Wraparound

References#

https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1794.html

Exploit#

No public exploit known

History#

Version 12026-09-01Record published in the CVE List.

Published

Published: 2026-09-01
Last modified: 2026-09-01

Vendor information

Vendor: Rockwell Automation
Product: RSLinx Classic®

All Rockwell Automation vulnerabilities

Score

9.2 Critical

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 37.3.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Memory Corruption

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
V4.50 and prior
Fixed
Not stated

Scoring System

CVSS v4.0

9.2 Critical

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Attack Requirements	None
Privileges Required	None
User Interaction	None
Vulnerable System Confidentiality	None
Vulnerable System Integrity	None
Vulnerable System Availability	High
Subsequent System Confidentiality	None
Subsequent System Integrity	None
Subsequent System Availability	High

CVSS v3.1

Not available

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).