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highMemory Corruption

CVE-2026-9622

CVE-2026-9622 — RSLinx Classic® - Multiple Vulnerabilities

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.

Published Updated Sources: NVD, Rockwell Automation (CNA), SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

0%

ahead of 0% of scored CVEs

Affects

Rockwell Automation

RSLinx Classic®

CVSS base

8.7

high

Remediation

The vendor's own words where we have them.

Upgrade RSLinx Classic® to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

  • Identify exposed assets running affected vendor/product/version combinations.
  • Prioritize based on EPSS, PoC availability, and external exposure.
  • Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

VendorProductVersionsStatus
Rockwell AutomationRSLinx Classic®V4.50 and priorVulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactSource
8.7CVSS 4.0highRockwell Automation (CNA)

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

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-191 · Integer Underflow (Wrap or Wraparound)

  • DoS: Crash, Exit, or Restart
  • DoS: Resource Consumption (CPU)
  • DoS: Resource Consumption (Memory)
  • DoS: Instability

Weakness & attack patterns

  • CWE-191

Inferred from the weakness class — not observed against this CVE.

CAPEC-100 · Overflow BuffersCAPEC-123 · Buffer Manipulation

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

  • Prioritize edge telemetry for network-reachable RSLinx Classic®.
web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

  1. 2026
  2. Added · CVSS 3.1 8.7 (AV:N)

    Sep 1, 2026 · NVD

  3. Initial · CVE published

    Sep 1, 2026 · NVD

  4. CVE published by MITRE.

    Sep 1, 2026 · SOCRadar CTI

References

1 on the record

Elsewhere on this site

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record1

What should defenders know first?

CVE-2026-9622 is RSLinx Classic® - Multiple Vulnerabilities, a high vulnerability affecting RSLinx Classic® from Rockwell Automation. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-9622. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-9622. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 8.7 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.