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CVE-2026-24423VulnerabilityPublished Updated

CVE-2026-24423: SmarterTools SmarterMail · Missing Authentication

Affects SmarterTools SmarterMailSource CVE Database V5

0

Exploited in the wild · used in ransomware campaigns · KEV due 26 Feb 2026 · public detection template (Nuclei) · 88% EPSS : upgrade to 100.0.9511 now.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score
9.3Critical
How severe the flaw is on the 0–10 CVSS scale.
KEV deadline
 US federal agencies must patch by this date; a sensible deadline for everyone else.
Ransomware
Used in ransomware campaigns
EPSS
88.1% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 100.0.9511
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 23 Jan 2026

  2. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  3. Exploited in the wild: evidence found.

    Listed in CISA KEV 13 days after disclosure

  4. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. CVE ID reserved

    by VulnCheck

    , 23 hours before disclosure

  2. CVE published

    on cve.org

    , t = 0

  3. In Threat Radar

    record ingested

    , 12 minutes after disclosure

  4. Added to CISA KEV (opens in a new tab)

    exploitation confirmed · ransomware use known

    , 13 days after disclosure

  5. KEV remediation due

    US federal deadline

    , 34 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Upgrade SmarterTools SmarterMail to 100.0.9511.

Affected software

ProductAffectedFixed in
SmarterToolsSmarterMailAffected
  • <100.0.9511
Fixed in
  • 100.0.9511

Description

SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the ConnectToHub API method. The attacker could point the SmarterMail to the malicious HTTP server, which serves the malicious OS command. This command will be executed by the vulnerable application.

References

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