CVE-2026-42393Hinoki check available

Secret-length disclosure via nonconstant-time comparison

Published Aug 28, 2026 · Updated Aug 28, 2026

Timing side channel in affected OX Dovecot CE and Pro releases allows remote attackers to learn doveadm password or API-key lengths. The doveadm credential comparison exposes input-length differences in response timing instead of fully masking comparison duration. Repeated accurately timed requests from the same network reveal only the configured secret's length, reducing the effort required to guess it.

CVSS severity3.1
Low
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Timing side channel in affected OX Dovecot CE and Pro releases allows remote attackers to learn doveadm password or API-key lengths. The doveadm credential comparison exposes input-length differences in response timing instead of fully masking comparison duration. Repeated accurately timed requests from the same network reveal only the configured secret's length, reducing the effort required to guess it.

The record

CVE
CVE-2026-42393
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
Open-Xchange GmbH
Product
OX Dovecot CE
Classifications
CWE-200
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 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=2.3.0 <2.4.5

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Open-Xchange GmbH · OX Dovecot CEversion=2.3.0 <2.4.5
Open-Xchange GmbH · OX Dovecot Proversion=2.3.0 <2.3.22.2; version=3.0.0 <3.0.7; version=3.1.0 <3.1.6

Published CVSS scores

3.1Open-Xchange GmbHCVSS:3.1/AV:A/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.

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No observations available

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

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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