CVE-2025-52691: SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 28 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 85.7%
EPSS score, percentile 99.7 of all scored records
- How severe?
- 10.0 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline . Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- SmarterMail versions Build 9406 and earlier
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA due date for this action: .
Solution (from the CVE record)
Users and administrators of affected product versions are advised to update to SmarterMail version Build 9413 immediately.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://www.smartertools.com/smartermail/release-notes/current
- https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2025-124/
- https://nvd.nist.gov/vuln/detail/CVE-2025-52691
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | SmarterMail versions Build 9406 and earlier |
Versions not listed are: unknown.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
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.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2025-52691 to its Known Exploited Vulnerabilities (KEV) catalog on 26 Jan 2026.
- CISA marks it as known to be used in ransomware campaigns.
- The due date CISA sets for the required action is 16 Feb 2026.
- The CVE record was published on 29 Dec 2025, 28 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 10.0 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 85.7% (percentile 99.7), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
Upload Arbitrary Files
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
- CWE-434: Unrestricted Upload of File with Dangerous Type
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
More exploited SmarterTools vulnerabilities
- CVE-2026-24423: SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability
- CVE-2026-23760: SmarterTools SmarterMail Authentication Bypass Using an Alternate Path or Channel Vulnerability