CVE-2026-24423
SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability - [Actively Exploited]
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.
INFO
Published Date :
Jan. 23, 2026, 5:16 p.m.
Last Modified :
Feb. 6, 2026, 4:45 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CISA KEV (Known Exploited Vulnerabilities)
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.
SmarterTools SmarterMail contains a missing authentication for critical function vulnerability in the ConnectToHub API method. This could allow the attacker to point the SmarterMail instance to a malicious HTTP server which serves the malicious OS command and could lead to command execution.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
https://www.smartertools.com/smartermail/release-notes/current ; https://www.cve.org/CVERecord?id=CVE-2026-24423 ; https://nvd.nist.gov/vuln/detail/CVE-2026-24423
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update SmarterMail to build 9511 or later.
- Validate ConnectToHub API method security.
- Monitor for suspicious server connections.
Public PoC/Exploit Available at Github
CVE-2026-24423 has a 3 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-24423.
| URL | Resource |
|---|---|
| https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermail | Third Party Advisory |
| https://www.smartertools.com/smartermail/release-notes/current | Release Notes |
| https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api | Third Party Advisory |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24423 | US Government Resource |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-24423 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-24423
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Mirror of https://github.com/nomi-sec/PoC-in-GitHub
CVE-2026-24423 exp
Python
None
PowerShell Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-24423 vulnerability anywhere in the article.
-
Daily CyberSecurity
Email Under Siege: Storm-2603 Exploits SmarterMail to Deploy Warlock Ransomware
A new report from ReliaQuest has uncovered a dangerous alliance between a China-based threat actor and a known ransomware strain. The group, identified as Storm-2603, has been caught actively exploiti ... Read more
-
The Hacker News
Warlock Ransomware Breaches SmarterTools Through Unpatched SmarterMail Server
SmarterTools confirmed last week that the Warlock (aka Storm-2603) ransomware gang breached its network by exploiting an unpatched SmarterMail instance. The incident took place on January 29, 2026, wh ... Read more
-
The Cyber Express
SmarterTools Breached by Own SmarterMail Vulnerabilities
SmarterTools was breached by hackers exploiting a vulnerability in its own SmarterMail software through an unknown virtual machine set up by an employee that wasn’t being updated. “Prior to the breach ... Read more
-
Help Net Security
Ransomware group breached SmarterTools via flaw in its SmarterMail deployment
SmarterTools, the company behind the popular Microsoft Exchange alternative SmarterMail, has been breached by a ransomware-wielding group that leveraged a recently fixed vulnerability in that solution ... Read more
-
The Register
Telcos aren't saying how they fought back against China's Salt Typhoon attacks
Infosec In Brief So-hot-right-now AI assistant OpenClaw, which is very much not secure right now, has teamed up with security scanning service VirusTotal. The tie-up means “skills” in the ClawHub – cu ... Read more
-
Help Net Security
Week in review: Notepad++ supply chain attack details and targets, Patch Tuesday forecast
Here’s an overview of some of last week’s most interesting news, articles, interviews and videos: Global Threat Map: Open-source real-time situational awareness platform Global Threat Map is an open-s ... Read more
-
TheCyberThrone
CISA Adds SmarterMail and React Native CLI Flaws to KEV Catalog
February 6, 2026U.S. CISA has escalated two critical vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, signaling active exploitation in the wild. CVE-2026-24423 in SmarterTools Sma ... Read more
-
Help Net Security
Poland’s energy control systems were breached through exposed VPN access
On 29 December 2025, coordinated cyberattacks unfolded across Poland’s critical infrastructure, targeting energy and industrial organizations. The attackers struck numerous wind and solar farms, a pri ... Read more
-
Help Net Security
Ransomware attackers are exploiting critical SmarterMail vulnerability (CVE-2026-24423)
For the third time in two weeks, CISA added a vulnerability (CVE-2026-24423) affecting SmarterTools’ SmarterMail email and collaboration server to its Known Exploited Vulnerabilities catalog, and this ... Read more
-
security.nl
SmarterMail-servers aangevallen via kritieke RCE-kwetsbaarheid
Aanvallers maken actief misbruik van een kritieke kwetsbaarheid in SmarterMail waardoor kwetsbare servers op afstand zijn over te nemen, zo waarschuwt het Amerikaanse cyberagentschap CISA. Drie weken ... Read more
-
The Hacker News
SmarterMail Fixes Critical Unauthenticated RCE Flaw with CVSS 9.3 Score
SmarterTools has addressed two more security flaws in SmarterMail email software, including one critical security flaw that could result in arbitrary code execution. The vulnerability, tracked as CVE- ... Read more
The following table lists the changes that have been made to the
CVE-2026-24423 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 06, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:smartertools:smartermail:*:*:*:*:*:*:*:* versions up to (excluding) 100.0.9511 Added Reference Type VulnCheck: https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermail Types: Third Party Advisory Added Reference Type VulnCheck: https://www.smartertools.com/smartermail/release-notes/current Types: Release Notes Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api Types: Third Party Advisory Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24423 Types: US Government Resource -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Feb. 05, 2026
Action Type Old Value New Value Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24423 -
New CVE Received by [email protected]
Jan. 23, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-306 Added Reference https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermail Added Reference https://www.smartertools.com/smartermail/release-notes/current Added Reference https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api