CVE-2026-24423
SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 26 February 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 4.0
- 9.3 CRITICALCVSS:4.0/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/M
- EPSS
- 88.18% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 5 February 2026 · due 26 February 2026 · used in ransomware campaigns
- Weakness
- CWE-306
- Affected
- smartertools/smartermail
- Source
- disclosure@vulncheck.com
EPSS 88.2% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
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
References
- https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermailThird Party Advisory
- https://www.smartertools.com/smartermail/release-notes/currentRelease Notes
- https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-apiThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24423US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.