CVE-2026-24423Known exploitationPublic exploitNetwork attack vectorHinoki check available

Unauthenticated command execution via untrusted hub response

Published Jan 23, 2026 · Updated Jan 23, 2026

Missing authentication in SmarterMail before 100.0.9511 allows remote attackers to execute arbitrary OS commands through ConnectToHub. The SystemAdminSettingsController.ConnectToHub API accepts an unauthenticated hub address, fetches configuration from that server, and executes its CommandMount value as an operating-system command. The API must be network-reachable and the attacker must operate the referenced HTTP server; successful exploitation gives control of the mail-server host without credentials.

CVSS severity9.3
Critical
EPSS probability88.18%
Next 30 days · Nov 1, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Missing authentication in SmarterMail before 100.0.9511 allows remote attackers to execute arbitrary OS commands through ConnectToHub. The SystemAdminSettingsController.ConnectToHub API accepts an unauthenticated hub address, fetches configuration from that server, and executes its CommandMount value as an operating-system command. The API must be network-reachable and the attacker must operate the referenced HTTP server; successful exploitation gives control of the mail-server host without credentials.

The record

CVE
CVE-2026-24423
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
SmarterTools Inc.
Product
SmarterMail
Classifications
CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 2026Record updatedLatest update available in the CVE record.
  3. Feb 5, 2026Exploitation reportedCISA Known Exploited Vulnerabilities listing

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 <100.0.9511

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SmarterTools Inc. · SmarterMailversion=0 <100.0.9511

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA: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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsShadowserver observations through Sep 28, 2026. Gaps indicate unavailable data.
Sep 22, 2026Sep 28, 2026
View daily counts
Reporting dayUnique IPs
Sep 22, 20264
Sep 23, 20261
Sep 24, 2026Unavailable
Sep 25, 20261
Sep 26, 2026Unavailable
Sep 27, 20263
Sep 28, 20265
Latest reporting daySep 28, 2026
Latest daily unique IPs5
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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