SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability
SmarterTools — SmarterMail
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.
9.3
87.7%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (Vulnerable System)
- High
- Integrity (Vulnerable System)
- High
- Availability (Vulnerable System)
- High
- Confidentiality (Subsequent System)
- None
- Integrity (Subsequent System)
- None
- Availability (Subsequent System)
- None
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
- Published
- Jan 23, 2026
- Modified
- Mar 5, 2026
- Added to KEV
- Feb 5, 2026
- Federal patch due
- Feb 26, 2026
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2026-24423, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2026-24423 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2026-24423?
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.
How severe is CVE-2026-24423?
CVE-2026-24423 has a CVSS base score of 9.3 out of 10 (CVSS 4.0).
Is CVE-2026-24423 actively exploited in the wild?
Yes. CVE-2026-24423 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Feb 5, 2026, meaning CISA has confirmed evidence of active exploitation. It is also flagged as used in ransomware campaigns.
What is the EPSS score for CVE-2026-24423?
87.7% - meaning FIRST.org's EPSS model estimates a 87.7% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2026-24423?
Yes - a public Nuclei template referencing CVE-2026-24423 exist in public repositories we checked.
What type of vulnerability is CVE-2026-24423?
CVE-2026-24423 is classified under CWE-306 (CWE-306 Missing Authentication for Critical Function).
Cross-checked against
Impactr finds and proves whether CVE-2026-24423 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
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