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CWE-521Weakness · CWE-521

CVE-2026-6284

CRITICAL · 9.1 CVSS v3.1 Published 2026-04-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An attacker with network access to the PLC is able to brute force discover passwords to gain unauthorized access to systems and services. The limited password complexity and no password input limiters makes brute force password enumeration possible.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This CVE describes a critical authentication weakness in PLC (Programmable Logic Controller) firmware where lack of rate limiting, account lockout mechanisms, and minimal password complexity requirements allows remote attackers to perform brute force password attacks. An attacker with network access can use automated tools to enumerate credentials until gaining unauthorized access to the industrial control device and connected systems.

MitigationImplement account lockout policies after failed login attempts, enforce strong password complexity requirements, add rate limiting to authentication endpoints, and consider network segmentation to limit exposure of PLC management interfaces.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify PLC device and firmware version
    Locate the PLC device on the network and retrieve its firmware version via the device's web interface, console, or SNMP. Common commands include accessing /about or status pages, or using vendor-specific CLI commands like 'show version' or 'system info'.
    Affected if The firmware version is unknown or cannot be determined, making it impossible to compare against any published advisory versions.
  2. Verify rate limiting configuration on authentication endpoints
    Access the PLC web management interface or console and navigate to security or authentication settings. Look for any rate limiting, request throttling, or login attempt frequency controls. Check configuration files if accessible via FTP, SMB, or API.
    Affected if No rate limiting or throttling mechanism is found or enabled on login/authentication endpoints.
  3. Confirm account lockout policy status
    In the PLC security or user management settings, locate account lockout or login attempt lockout policies. Verify whether a lockout threshold (e.g., lock after 5 failed attempts) and lockout duration are configured.
    Affected if No account lockout mechanism exists or it is explicitly disabled, allowing unlimited failed login attempts.
  4. Inspect password complexity requirements
    Check the user account or password policy settings within the PLC management interface. Look for minimum length, character type requirements (uppercase, lowercase, numbers, symbols), and any password strength validation.
    Affected if Password complexity requirements are absent, minimal (e.g., less than 8 characters), or allow trivial passwords.
  5. Assess network exposure of PLC management interfaces
    Scan the network for open ports on the PLC device commonly used for management (HTTP/HTTPS ports 80/443, Telnet 23, SSH 22, or vendor-specific ports). Verify if these interfaces are accessible from untrusted networks or the internet.
    Affected if PLC management interfaces are reachable from untrusted networks without firewall filtering.

The environment is affected if the PLC has no rate limiting, no account lockout policy, weak or absent password complexity requirements, and the management interface is network-accessible to potential attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement account lockout policies after failed login attempts, enforce strong password complexity requirements, add rate limiting to authentication endpoints, and consider network segmentation to limit exposure of PLC management interfaces.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-6284 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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