known ransomware use

SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability

Added to KEV
2026-02-05
Federal due date
2026-02-26
Vendor
SmarterTools
Product
SmarterMail
EPSS
99.3th percentile (score 0.834, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2026-24423

CISA short description

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.

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.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.