CVE-2025-52691Upload Arbitrary Files
- 10.0CriticalCVSS base score
- 85.7%Exploitation in 30 daysEPSS · top 0.3% of all CVEs
- YesKnown exploitedin CISA's KEV since 26 Jan 2026
- 2Public exploitsMetasploit, Nuclei and Exploit-DB
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability.
- Added
- 26 Jan 2026
- Fix due (US federal)
- 16 Feb 2026
- Used by ransomware
- Known
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV, since 26 Jan 2026.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Metasploit module and a Nuclei template for it. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: it is being exploited.
Show the exploits3
Metasploit modules1 module
- SmarterTools SmarterMail GUID File Upload Vulnerability (Metasploit module) (opens in a new tab)
exploit/multi/http/smartermail_guid_file_uploadRank excellentdisclosed 9 Oct 2025
Nuclei templates1 template
- SmarterMail - Unrestricted File Upload (Nuclei template) (opens in a new tab)
http/cves/2025/CVE-2025-52691.yamlSeverity critical
References tagged exploit1 reference
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By CSA
- 6 months later
· 6 months later
Published
- 28 days later
· 28 days later
Added to CISA KEV
Known exploited, also by ransomware
- 31 days later
· 31 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CSACNA (assigner) | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 85.7% · top 0.3% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 10.0.
Affected products
- affected SmarterMail versions Build 9406 and earlier
What to do
Solution: Users and administrators of affected product versions are advised to update to SmarterMail version Build 9413 immediately.
References
References3
- https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2025-124/ (opens in a new tab)
- https://github.com/watchtowrlabs/watchTowr-vs-SmarterMail-CVE-2025-52691?ref=labs.watchtowr.com (opens in a new tab)exploit
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-52691 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-205544 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-52691)Record last updated .