CVE-2026-23767Network attack vector

Unauthenticated command execution via unrestricted TCP/9100 input

Published Mar 5, 2026 · Updated Mar 5, 2026

Missing authentication in ESC/POS on networked POS printers allows remote attackers to execute commands over TCP port 9100. The protocol accepts plaintext printer commands from any network host without authenticating the sender, authorizing commands, or protecting message integrity. Network reachability is required; successful use permits unintended printer operations, access to device-stored information, or interception and tampering in transit.

CVSS severity9.8
Critical
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in ESC/POS on networked POS printers allows remote attackers to execute commands over TCP port 9100. The protocol accepts plaintext printer commands from any network host without authenticating the sender, authorizing commands, or protecting message integrity. Network reachability is required; successful use permits unintended printer operations, access to device-stored information, or interception and tampering in transit.

The record

CVE
CVE-2026-23767
Published
Mar 5, 2026
Updated
Mar 5, 2026
Vendor
Seiko Epson Corporation
Product
ESC/POS
Classifications
CWE-284, CWE-319, CWE-306, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 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=All products implementing ESC/POS

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Seiko Epson Corporation · ESC/POSversion=All products implementing ESC/POS

Published CVSS scores

9.8CISA-ADPCVSS: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-284Improper Access Control
CWE-319Cleartext Transmission of Sensitive Information
CWE-306Missing Authentication for Critical Function
T1040Network Sniffing

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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