Which products and versions are affected by CVE-2021-22681?

Affected: Factorytalk Services Platform (Rockwellautomation); Rslogix 5000 (Rockwellautomation); Studio 5000 Logix Designer (Rockwellautomation), among others. The full list is in the CVE brief.

Is CVE-2021-22681 being exploited in the wild?

It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 5, 2026.

Is CVE-2021-22681 in the CISA KEV catalog?

Yes. It was added on Mar 5, 2026 with a federal remediation due date of Mar 26, 2026.

Is there a public exploit for CVE-2021-22681?

Public exploit code is available.

Is there a fix for CVE-2021-22681?

Fixed versions are available, including Rslogix 5000 20.

How urgently should CVE-2021-22681 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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Vulnerability Intelligence

CVE-2021-22681

CriticalExploitedPublic exploit

Published Feb 26, 2021 · Updated Mar 6, 2026 · Also known as TR-21-0181

Key Facts

Patch immediately

CVE-2021-22681 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Factorytalk Services Platform (Rockwellautomation), Rslogix 5000 (Rockwellautomation), Studio 5000 Logix Designer (Rockwellautomation) and 1 more product.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 5, 2026. Public exploit code is available.
EPSS estimates a 64% probability of exploitation in the next 30 days.
Fixed versions are available, including Rslogix 5000 20.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

9.8

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS (30-day exploit likelihood)

64%

Higher than 99.2% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2021-22681 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

Rockwell Automation Studio 5000 Logix Designer Versions 21 and later, and RSLogix 5000 Versions 16 through 20 use a key to verify Logix controllers are communicating with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800. Rockwell Automation Studio 5000 Logix Designer Versions 21 and later and RSLogix 5000: Versions 16 through 20 are vulnerable because an unauthenticated attacker could bypass this verification mechanism and authenticate with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800.

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
CISA KEV	Mar 5, 2026	Mar 26, 2026	Not reported
Industry KEV feed	Mar 5, 2026	Mar 26, 2026	Not reported
CIRCL KEV	Mar 5, 2026	Mar 26, 2026	Not reported
ENISA EUVD	Mar 5, 2026	n/a	Not reported

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Affected Products

4 affected entries in total

Product	Affected versions	Fixed in
Factorytalk Services PlatformRockwellautomation	See advisory	n/a
Rslogix 5000Rockwellautomation	See advisory	20
Studio 5000 Logix DesignerRockwellautomation	See advisory	n/a
Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers	>= RSLogix 5000 Versions 16 through 20	n/a

Patched Releases

Rslogix 5000

Timeline

Publicly disclosed
Feb 26, 2021
Added to CISA KEV
Mar 5, 2026
Added to Industry KEV feed
Mar 5, 2026
Added to CIRCL KEV
Mar 5, 2026
Added to ENISA EUVD
Mar 5, 2026
Last updated
Mar 6, 2026

Weakness Type

CWE-522 Insufficiently Protected Credentials

References

5 more references in the full CVE brief

FAQ

Common Questions.

Rockwell Automation Studio 5000 Logix Designer Versions 21 and later, and RSLogix 5000 Versions 16 through 20 use a key to verify Logix controllers are communicating with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLo…
Affected: Factorytalk Services Platform (Rockwellautomation); Rslogix 5000 (Rockwellautomation); Studio 5000 Logix Designer (Rockwellautomation), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 5, 2026.
Yes. It was added on Mar 5, 2026 with a federal remediation due date of Mar 26, 2026.
Public exploit code is available.
Fixed versions are available, including Rslogix 5000 20.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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