SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability
SmarterTools — SmarterMail
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.
10.0
85.5%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Published
- Dec 29, 2025
- Modified
- Feb 26, 2026
- Added to KEV
- Jan 26, 2026
- Federal patch due
- Feb 16, 2026
CISA 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.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2025-52691, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2025-52691 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2025-52691?
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.
How severe is CVE-2025-52691?
CVE-2025-52691 has a CVSS base score of 10.0 out of 10 (CVSS 3.1).
Is CVE-2025-52691 actively exploited in the wild?
Yes. CVE-2025-52691 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jan 26, 2026, meaning CISA has confirmed evidence of active exploitation. It is also flagged as used in ransomware campaigns.
What is the EPSS score for CVE-2025-52691?
85.5% - meaning FIRST.org's EPSS model estimates a 85.5% probability this vulnerability will be exploited in the wild within 30 days (100% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2025-52691?
Yes - a public Nuclei template referencing CVE-2025-52691 exist in public repositories we checked.
What type of vulnerability is CVE-2025-52691?
CVE-2025-52691 is classified under CWE-434 (CWE-434 Unrestricted Upload of File with Dangerous Type).
Cross-checked against
Impactr finds and proves whether CVE-2025-52691 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
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