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CVE-2025-52691VulnerabilityPublished Updated

CVE-2025-52691: SmarterTools SmarterMail · Unrestricted File Upload

Affects SmarterTools SmarterMailSource CVE Database V5

0

Exploited in the wild · used in ransomware campaigns · KEV due 16 Feb 2026 · public exploit available (Metasploit) · 85% EPSS : apply the vendor's fix or mitigations to SmarterTools SmarterMail now.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score
10.0Critical
How severe the flaw is on the 0–10 CVSS scale.
KEV deadline
 US federal agencies must patch by this date; a sensible deadline for everyone else.
Ransomware
Used in ransomware campaigns
EPSS
85.6% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 29 Dec 2025

  2. Weaponised: evidence found.

    1 Metasploit module

  3. Exploited in the wild: evidence found.

    Listed in CISA KEV 28 days after disclosure

  4. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. CVE ID reserved

    by CSA

    , 193 days before disclosure

  2. CVE published

    on cve.org

    , t = 0

  3. In Threat Radar

    record ingested

    , 44 hours after disclosure

  4. Added to CISA KEV (opens in a new tab)

    exploitation confirmed · ransomware use known

    , 28 days after disclosure

  5. KEV remediation due

    US federal deadline

    , 49 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

What to do

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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.

References

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