known ransomware use

SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability

Added to KEV
2026-01-26
Federal due date
2026-02-16
Vendor
SmarterTools
Product
SmarterMail
EPSS
99.6th percentile (score 0.897, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2025-52691

CISA short description

SmarterTools SmarterMail contains an unrestricted upload of file with dangerous type vulnerability that could allow an unauthenticated attacker to upload arbitrary files to any location on the mail server, potentially enabling remote code 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.