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Known Exploited Vulnerability
10.0
CRITICAL CVSS 3.1
CVE-2025-52691
SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability - [Actively Exploited]
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.

INFO

Published Date :

Dec. 29, 2025, 3:15 a.m.

Last Modified :

Jan. 27, 2026, 3:28 p.m.

Remotely Exploit :

Yes !

Source :

5f57b9bf-260d-4433-bf07-b6a79e9bb7d4
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

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.

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.

Notes :

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

The following products are affected by CVE-2025-52691 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Smartertools smartermail
: Total Affected Vendor : 1 | Products : 1
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL 5f57b9bf-260d-4433-bf07-b6a79e9bb7d4
Solution
Address improper access controls to prevent unauthorized file uploads and potential remote code execution.
  • Enforce strict authentication for file upload functionality.
  • Validate file types and sizes before upload.
  • Restrict upload locations to designated directories.
  • Apply vendor patches or updates for the mail server.
Public PoC/Exploit Available at Github

CVE-2025-52691 has a 13 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-52691.

URL Resource
https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2025-124/ Third Party Advisory
https://github.com/watchtowrlabs/watchTowr-vs-SmarterMail-CVE-2025-52691?ref=labs.watchtowr.com Exploit Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-52691 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-52691 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-52691 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Profile Photo
ninjazan420/CVE-2025-52691-PoC-SmarterMail-authentication-bypass-exploit-WT-2026-0001

CVE-2025-52691 PoC: Based on watchtowr's article WT-2026-0001 about an authentication bypass exploit, this one is a functional Python attack script.

Shell Python

Updated: 2 weeks, 5 days ago
0 stars 0 fork 0 watcher
Born at : Jan. 23, 2026, 11:48 a.m. This repo has been linked 1 different CVEs too.
Profile Photo
watchtowrlabs/watchTowr-vs-SmarterMail-CVE-2025-52691

None

Python

Updated: 4 weeks, 1 day ago
11 stars 1 fork 1 watcher
Born at : Jan. 8, 2026, 11:42 a.m. This repo has been linked 1 different CVEs too.
Profile Photo
nxgn-kd01/smartermail-cve-scanner

CVE-2025-52691 Scanner - Detects vulnerable SmarterMail installations (CVSS 10.0 RCE)

JavaScript Shell

Updated: 1 month, 1 week ago
1 stars 0 fork 0 watcher
Born at : Jan. 5, 2026, 1:46 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
rxerium/rxerium-templates

Nuclei scripts created by @rxerium for zero days / actively exploited vulnerabilities.

kev nuclei zero-day vkev

Updated: 1 month ago
32 stars 5 fork 5 watcher
Born at : Jan. 2, 2026, 5:37 p.m. This repo has been linked 3 different CVEs too.
Profile Photo
hilwa24/CVE-2025-52691

CVE‑2025‑52691 - SmarterMail Arbitrary File Upload Vulnerability

cve-2025-52691

Python

Updated: 1 month, 1 week ago
0 stars 0 fork 0 watcher
Born at : Dec. 31, 2025, 7:01 a.m. This repo has been linked 1 different CVEs too.
Profile Photo
sajjadsiam/CVE-2025-52691-poc

None

Python

Updated: 1 month ago
2 stars 0 fork 0 watcher
Born at : Dec. 30, 2025, 6:37 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
DeathShotXD/CVE-2025-52691-APT-PoC

An enhanced proof-of-concept exploit for CVE-2025-52691 (SmarterMail Arbitrary File Upload RCE) with APT-level features like stealth obfuscation, persistence, exfiltration, and interactive mode. For educational and authorized testing only. Credits to the original PoC by yt2w/CVE-2025-52691.

Python

Updated: 1 month, 1 week ago
4 stars 1 fork 1 watcher
Born at : Dec. 30, 2025, 6:21 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
you-ssef9/CVE-2025-52691

This repository contains a safe Proof of Concept (PoC) to detect vulnerable SmarterMail versions affected by CVE‑2025‑52691. The script performs version detection only and does not exploit the vulnerability.

Python

Updated: 1 month, 1 week ago
0 stars 0 fork 0 watcher
Born at : Dec. 30, 2025, 2:58 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
Ashwesker/Ashwesker-CVE-2025-52691

CVE-2025-52691

Updated: 1 month, 1 week ago
0 stars 1 fork 1 watcher
Born at : Dec. 30, 2025, 10:24 a.m. This repo has been linked 1 different CVEs too.
Profile Photo
rxerium/CVE-2025-52691

Detection for CVE-2025-52691

critical nuclei smartermail vulnerability

Updated: 1 month, 1 week ago
15 stars 4 fork 4 watcher
Born at : Dec. 30, 2025, 6:13 a.m. This repo has been linked 1 different CVEs too.
Profile Photo
yt2w/CVE-2025-52691

None

Python

Updated: 1 month, 1 week ago
3 stars 1 fork 1 watcher
Born at : Dec. 29, 2025, 4:23 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
rxerium/stars

A list of all of my starred repos, automated using Github Actions 🌟

github-actions stars

Updated: 1 week, 4 days ago
0 stars 0 fork 0 watcher
Born at : Jan. 4, 2023, 11:20 a.m. This repo has been linked 39 different CVEs too.
Profile Photo
nomi-sec/PoC-in-GitHub

📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.

security cve exploit poc vulnerability

Updated: 1 month ago
7462 stars 1233 fork 1233 watcher
Born at : Dec. 8, 2019, 1:03 p.m. This repo has been linked 826 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-52691 vulnerability anywhere in the article.

  • The Hacker News
Warlock Ransomware Breaches SmarterTools Through Unpatched SmarterMail Server

SmarterTools confirmed last week that the Warlock (aka Storm-2603) ransomware gang breached its network by exploiting an unpatched SmarterMail instance. The incident took place on January 29, 2026, wh ... Read more

Published Date: Feb 10, 2026 (2 days, 6 hours ago)
  • The Register
Telcos aren't saying how they fought back against China's Salt Typhoon attacks

Infosec In Brief So-hot-right-now AI assistant OpenClaw, which is very much not secure right now, has teamed up with security scanning service VirusTotal. The tie-up means “skills” in the ClawHub – cu ... Read more

Published Date: Feb 08, 2026 (3 days, 17 hours ago)
  • Help Net Security
Ransomware attackers are exploiting critical SmarterMail vulnerability (CVE-2026-24423)

For the third time in two weeks, CISA added a vulnerability (CVE-2026-24423) affecting SmarterTools’ SmarterMail email and collaboration server to its Known Exploited Vulnerabilities catalog, and this ... Read more

Published Date: Feb 06, 2026 (6 days, 5 hours ago)
  • Daily CyberSecurity
CISA Warns of Unpatched Avation & RISS Critical Flaws

In a concerning update for the operational technology (OT) sector, the Cybersecurity and Infrastructure Security Agency (CISA) has issued alerts for two distinct critical infrastructure devices where ... Read more

Published Date: Feb 05, 2026 (1 week ago)
  • Daily CyberSecurity
Broadcast Hijack: Critical KiloView Flaw (CVSS 9.8) Grants Full Control

The Cybersecurity and Infrastructure Security Agency (CISA) has issued a high-priority alert regarding a maximum-severity vulnerability in KiloView, a popular brand of video encoding and streaming dev ... Read more

Published Date: Feb 03, 2026 (1 week, 2 days ago)
  • CybersecurityNews
Metasploit Releases 7 New Exploit Modules covering FreePBX, Cacti and SmarterMail

The latest update to the Metasploit Framework this week provides a significant enhancement for penetration testers and red teamers, introducing seven new exploit modules targeting commonly used enterp ... Read more

Published Date: Jan 31, 2026 (1 week, 5 days ago)
  • Daily CyberSecurity
CVE-2026-24002: Critical Sandbox Escape Turns Grist Spreadsheets into RCE Weapons

A seemingly innocent spreadsheet formula could be the key to compromising entire organizations, thanks to a critical vulnerability uncovered by Cyera Research Labs in Grist-Core. The flaw, tracked as ... Read more

Published Date: Jan 29, 2026 (2 weeks ago)
  • Daily CyberSecurity
CVE-2026-23830: Critical SandboxJS Flaw (CVSS 10) Allows Total Sandbox Escape

A perfect storm of missing checks has led to a maximum-severity vulnerability in SandboxJS, a library designed to safely execute untrusted JavaScript code. Tracked as CVE-2026-23830, the flaw carries ... Read more

Published Date: Jan 29, 2026 (2 weeks ago)
  • Daily CyberSecurity
CVE-2025-14988: Critical 9.8 Vulnerability hits ibaPDA Industrial Software

A critical security vulnerability has been identified in ibaPDA, a core data acquisition system used in industrial environments to monitor and analyze process data. Tracked as CVE-2025-14988, the flaw ... Read more

Published Date: Jan 29, 2026 (2 weeks ago)
  • BleepingComputer
Over 6,000 SmarterMail servers exposed to automated hijacking attacks

Nonprofit security organization Shadowserver has found over 6,000 SmarterMail servers exposed online and likely vulnerable to attacks exploiting a critical authentication bypass vulnerability. Cyberse ... Read more

Published Date: Jan 27, 2026 (2 weeks, 2 days ago)
  • TheCyberThrone
CISA KEV Catalog Update – 5 Vulnerabilities Added

January 27, 20261) CVE-2018-14634 – Linux Kernel Integer Overflow (Local Privilege Escalation)Type: Integer overflow in the Linux kernel’s create_elf_tables() function.Impact: A local, unprivileged us ... Read more

Published Date: Jan 27, 2026 (2 weeks, 2 days ago)
  • Daily CyberSecurity
High-Severity DoS Flaw Hits Google Protocol Buffers (CVE-2026-0994)

A high-severity vulnerability has been discovered in Protocol Buffers (protobuf), Google’s widely used mechanism for serializing structured data. The flaw, tracked as CVE-2026-0994, affects Python imp ... Read more

Published Date: Jan 27, 2026 (2 weeks, 2 days ago)
  • BleepingComputer
SmarterMail auth bypass flaw now exploited to hijack admin accounts

Hackers began exploiting an authentication bypass vulnerability in SmarterTools' SmarterMail email server and collaboration tool that allows resetting admin passwords. An authentication bypass vulnera ... Read more

Published Date: Jan 22, 2026 (2 weeks, 6 days ago)
  • Huntress
Huntress Catches SmarterMail Account Takeover Leading to RCE

Background / Summary The Huntress DE&TH (Detection Engineering and Threat Hunting) Team has observed in-the-wild exploitation of a privileged account takeover vulnerability (CVE-2026-23760) in Smarter ... Read more

Published Date: Jan 22, 2026 (3 weeks ago)
  • Daily CyberSecurity
“Enjoy Your Admin Access”: Critical SmarterMail RCE Exploited in the Wild

Just weeks after a major vulnerability rocked the SmarterMail ecosystem, security researchers have uncovered a new, critical flaw that is already being weaponized in the wild. watchTowr Labs researche ... Read more

Published Date: Jan 22, 2026 (3 weeks ago)
  • The Hacker News
SmarterMail Auth Bypass Exploited in the Wild Two Days After Patch Release

A new security flaw in SmarterTools SmarterMail email software has come under active exploitation in the wild, two days after the release of a patch. The vulnerability, which currently does not have a ... Read more

Published Date: Jan 22, 2026 (3 weeks ago)
  • Daily CyberSecurity
Industrial Alert: Critical RCE in AVEVA Software Rated CVSS 10

AVEVA, a global leader in industrial software, has issued a critical security bulletin regarding its flagship Process Optimization software (formerly known as ROMeo). The alert details multiple vulner ... Read more

Published Date: Jan 20, 2026 (3 weeks, 2 days ago)
  • Daily CyberSecurity
CVE-2026-0695: High-Severity XSS Flaw Patched in ConnectWise PSA 2026.1

ConnectWise has released a crucial security update for its Professional Services Automation (PSA) platform, addressing two significant vulnerabilities that could allow attackers to weaponize mundane a ... Read more

Published Date: Jan 19, 2026 (3 weeks, 3 days ago)
  • security.nl
Zevenduizend SmarterMail-servers missen update voor zeer kritiek lek

Ruim zevenduizend SmarterMail-servers, waarvan zo'n veertig in Nederland, missen een beveiligingsupdate voor een zeer kritieke kwetsbaarheid waardoor een ongeauthenticeerde aanvaller de server op afst ... Read more

Published Date: Jan 14, 2026 (4 weeks, 1 day ago)
  • CybersecurityNews
8000+ SmarterMail Hosts Vulnerable to RCE Attack – PoC Exploit Released

Over 8,000 internet-exposed SmarterMail servers remain vulnerable to a critical remote code execution flaw tracked as CVE-2025-52691, according to scans conducted on January 12, 2026. Security researc ... Read more

Published Date: Jan 13, 2026 (4 weeks, 2 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2025-52691 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Modified Analysis by [email protected]

    Jan. 27, 2026

    Action Type Old Value New Value
    Added Reference Type CISA-ADP: https://github.com/watchtowrlabs/watchTowr-vs-SmarterMail-CVE-2025-52691?ref=labs.watchtowr.com Types: Exploit, Third Party Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-52691 Types: US Government Resource
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 26, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-52691
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 22, 2026

    Action Type Old Value New Value
    Removed Reference https://labs.watchtowr.com/attackers-with-decompilers-strike-again-smartertools-smartermail-wt-2026-0001-auth-bypass/
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 22, 2026

    Action Type Old Value New Value
    Added Reference https://labs.watchtowr.com/attackers-with-decompilers-strike-again-smartertools-smartermail-wt-2026-0001-auth-bypass/
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jan. 08, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/watchtowrlabs/watchTowr-vs-SmarterMail-CVE-2025-52691?ref=labs.watchtowr.com
  • Initial Analysis by [email protected]

    Jan. 02, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:smartertools:smartermail:*:*:*:*:*:*:*:* versions up to (excluding) 100.0.9413
    Added Reference Type CSA: https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2025-124/ Types: Third Party Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Dec. 29, 2025

    Action Type Old Value New Value
    Added CWE CWE-434
  • New CVE Received by 5f57b9bf-260d-4433-bf07-b6a79e9bb7d4

    Dec. 29, 2025

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    Added Reference https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2025-124/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 10
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact