Vulnerability record

CVE-2025-52691

SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability

Severity: CriticalExploitation: Exploitation confirmedCISA KEV Used by ransomware
What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run SmarterMail, fix it now.

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.

US federal civilian agencies must remediate by Feb 16, 2026.

Patch status

No official fix confirmed yet

Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.

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.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
ProductVendorAffected versionsFixed inSource
SmarterMailSmarterTools< 100.0.9413100.0.9413KEV

Sources: KEV = CISA Known Exploited Vulnerabilities catalog.

Intelligence timeline

Developments from the last 30 days, newest first.

  1. CVSS scoredUpdateKEV

    CVE-2025-52691 scored CVSS 10.0: SmarterTools SmarterMail, SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability

    CISA lists this as exploited in the wild and known to be used in ransomware campaigns. Unpatched SmarterMail systems are exposed to active attacks now.

    Basis: NIST National Vulnerability Database

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

  • smartertools.com https://www.smartertools.com/smartermail/release-notes/current
  • csa.gov.sg https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2025-124/
  • nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2025-52691
  • github.com https://github.com/watchtowrlabs/watchTowr-vs-SmarterMail-CVE-2025-52691?ref=labs.watchtowr.com
  • cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-52691