CVE-2025-52691
Unrestricted Upload of File with Dangerous Type in SmarterTools SmarterMail. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 26 January 2026.
- Product
- SmarterTools SmarterMail
- Added to CISA's catalog
- Federal fix-by date
- Ransomware
- Known to be used in ransomware
- Vendor advisories
- Sources
- CISA’s catalog, NVD entry
CISA’s 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.
More from SmarterTools this year.
- CVE-2026-24423 Missing Authentication for Critical Function, added
- CVE-2026-23760 Authentication Bypass Using an Alternate Path or Channel, added
Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 3 November 2026.