January 26, 2026 · Applied Cybernetics Group
CVE-2025-52691 — SmarterTools SmarterMail
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
- 99.7th percentile (score 0.855, as of
2026-07-13) - NVD CVSS v3.1
- 10 (CRITICAL)
- 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.
NVD description
Successful exploitation of the vulnerability could allow an unauthenticated attacker to upload arbitrary files to any location on the mail server, potentially enabling remote code execution.