CVE-2026-73542Network attack vector

Communication disclosure via revoked root certificate trust

Published Aug 20, 2026 · Updated Aug 20, 2026

Improper certificate validation in SEIKO EPSON printers and scanners allows man-in-the-middle attackers to read transmitted data. Revoked root certificates remain in the device trust store, causing it to trust a spoofed certificate-distribution server and import a forged certificate. The attacker must control the network path before the device retrieves the forged certificate; subsequent outbound communications can then be intercepted and decrypted.

CVSS severity6.3
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in SEIKO EPSON printers and scanners allows man-in-the-middle attackers to read transmitted data. Revoked root certificates remain in the device trust store, causing it to trust a spoofed certificate-distribution server and import a forged certificate. The attacker must control the network path before the device retrieves the forged certificate; subsequent outbound communications can then be intercepted and decrypted.

The record

CVE
CVE-2026-73542
Published
Aug 20, 2026
Updated
Aug 20, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-296, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.3JPCERT/CCCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
3.7JPCERT/CCCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

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-296Improper Following of a Certificate's Chain of Trust
T1557Adversary-in-the-Middle

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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