CVE-2026-21718Network attack vector

Unauthenticated code execution via predictable administrator passwords

Published Feb 27, 2026 · Updated Feb 27, 2026

Authentication bypass in Copeland XWEB PRO 1.12.1 and earlier allows remote attackers to execute code as an administrator. The firmware derives daily web and SSH administrator passwords by hashing hard-coded seeds with the device MAC address and current date. Network access is sufficient because public endpoints expose the variable inputs, allowing derived credentials to open the web interface, SSH, or Shellinabox.

CVSS severity9.8
Critical
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Copeland XWEB PRO 1.12.1 and earlier allows remote attackers to execute code as an administrator. The firmware derives daily web and SSH administrator passwords by hashing hard-coded seeds with the device MAC address and current date. Network access is sufficient because public endpoints expose the variable inputs, allowing derived credentials to open the web interface, SSH, or Shellinabox.

The record

CVE
CVE-2026-21718
Published
Feb 27, 2026
Updated
Feb 27, 2026
Vendor
Copeland LP
Product
XWEB 300D PRO
Classifications
CWE-327, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.12.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Copeland LP · XWEB 300D PROversion=0 <=1.12.1
Copeland LP · XWEB 500D PROversion=0 <=1.12.1
Copeland LP · XWEB 500B PROversion=0 <=1.12.1

Published CVSS scores

10.0CISA ICS-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-327Use of a Broken or Risky Cryptographic Algorithm
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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