On 2026-01-26, CISA added CVE-2025-52691 (SmarterTools SmarterMail) to its Known Exploited Vulnerabilities (KEV) catalog [2]. The vulnerability is listed in the catalog as "SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability" [2]. CISA requires applying mitigations in accordance with vendor instructions; see the full text below for specific requirements [2].
Backfill: this event became public on Jan 26, 2026 and we added it on Nov 10, 2026. It is not a new event.
CISA Adds SmarterTools SmarterMail Vulnerability CVE-2025-52691 to Known Exploited Vulnerabilities Catalog
1 min read
- Disclosed
- Jan 26, 2026
- Published
- Nov 10, 2026
- Last updated
- Nov 8, 2026
- CVSS basis
- Our assessment
- 85.7%, higher than 100% of CVEs
- Exploitation and patch status
- ExploitedKEV
- Attack vector
- Vulnerability status
- Actor type
- Motivation
On this page
30-second summary
What happened
Who is affected
Industries mainly affected: Government, Cross-industry
What to do nowOur advice
CISA requires applying mitigations in accordance with vendor instructions; see the full text for specific requirements [2].
Timeline
Technical details
CISA KEV Listing
On 2026-01-26, CISA added CVE-2025-52691 to the Known Exploited Vulnerabilities () catalog for SmarterTools SmarterMail [2].
Original Technical 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 . [2]
Official Requirements
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. [2]
Individual Vulnerability Record
The U.S. National Vulnerability Database (NVD) provides an independent vulnerability record and description for CVE-2025-52691 [1].
References
Official / primary3
- [1]
“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.”
- [2]
This site aggregates public information and is not security consulting advice. Test remediation steps before applying.