CVE-2025-52691
Upload Arbitrary Files
- Critical 10.0
- Exploited: added to CISA KEV 26 Jan 2026
- Used in ransomware campaigns
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.
Key facts
- Published
- 29 Dec 2025
- Last changed
- 26 Feb 2026
- Assigned by
- CSA
- KEV added
- 26 Jan 2026
- KEV fix due
- 16 Feb 2026
- Used in ransomware
- Yes, according to CISA
- EPSS
- 85.655% likely to be exploited in the next 30 days, higher than 99.73% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: yes; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 10.0CVSS 3.1, Criticalfrom the CNA (CSA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
What to do
- Users and administrators of affected product versions are advised to update to SmarterMail version Build 9413 immediately.CNA solution statement
- 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 KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| SmarterTools | SmarterMail |
|
Timeline
- 29 Dec 2025 Published
- 26 Jan 2026 Added to the CISA KEV catalogue