VulnerabilityPublished 5 Mar 2026Updated 6 Mar 2026

CVE-2026-23767: Seiko Epson ESC/POS · Missing Authentication

Affects Seiko Epson ESC/POSSource CVE Database V5

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Not known to be exploited · CVSS 9.8 Critical.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

9.8Critical

How severe the flaw is on the 0–10 CVSS scale.

Contested

Critical score, yet low EPSS after six months

EPSS: 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Seiko Epson CorporationESC/POS	Affected =All products implementing ESC/POS	Fixed in–

AI-suggested

Since ESC/POS lacks built-in authentication and encryption, organizations should implement compensating controls to mitigate this vulnerability. Network segmentation is critical: isolate ESC/POS-enabled printers on dedicated VLANs or subnets with strict access controls to limit communication only to trusted devices and management systems. Employ network-level authentication and encryption mechanisms such as VPNs or IPsec tunnels to protect printer communications from interception and unauthorized access. Disable or restrict network access to printers from untrusted or public networks. Where possible, update printer firmware or vendor software to versions that may include enhanced security features or alternative protocols supporting authentication and encryption. Monitor network traffic for anomalous or unauthorized printer commands and implement intrusion detection systems tailored to detect ESC/POS command anomalies. Establish strict physical security controls to prevent local tampering. Finally, engage with vendors to advocate for secure protocol enhancements and timely patch releases.

Description

ESC/POS, a printer control language designed by Seiko Epson Corporation, lacks mechanisms for user authentication and command authorization, does not provide controls to restrict sources or destinations of network communication, and transmits commands without encryption or integrity protection.

Impact

The impact of CVE-2026-23767 is severe for organizations worldwide that utilize ESC/POS-enabled printers, especially in retail, hospitality, and financial sectors where point-of-sale devices are critical. Attackers can remotely execute arbitrary commands on printers, potentially leading to unauthorized disclosure of sensitive printed information, manipulation or deletion of print jobs, and disruption of printing services causing operational downtime. This can result in financial losses, reputational damage, and compliance violations if sensitive customer or transaction data is exposed. Additionally, compromised printers could be leveraged as pivot points within internal networks to launch further attacks or reconnaissance. The lack of encryption and authentication increases the risk of man-in-the-middle attacks and command injection from remote adversaries. Given the ubiquity of ESC/POS in POS environments globally, the threat surface is extensive and affects both small businesses and large enterprises.

References

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