CVE-2026-24423

Description

SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the ConnectToHub API method. The attacker could point the SmarterMail to the malicious HTTP server, which serves the malicious OS command. This command will be executed by the vulnerable application.

Overview

State: PUBLISHED
Assigner (CNA): VulnCheck
CVSS severity: CRITICAL
CVSS score: 9.3 / 10
CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Effective score: 9.3 / 10 CRITICAL source: CNA overview
CWE(s): CWE-306
Reserved: 2026-01-22
Published: 2026-01-23 16:53 UTC
Last updated: 2026-03-05 01:30 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/24xxx/CVE-2026-24423.json
Linked Threat: CVE-2026-24423 — SmarterTools SmarterMail: SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability

CISA Known Exploited Vulnerabilities CISA KEV

CISA has confirmed in-the-wild exploitation of this CVE. Federal agencies must remediate by the due date below; private orgs should treat it as priority-1.

Vulnerability name: SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability
Vendor / project: SmarterTools
Product: SmarterMail
Date added to KEV: 2026-02-05
Remediation due: 2026-02-26
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.
Ransomware campaign use: Known
CISA notes: https://www.smartertools.com/smartermail/release-notes/current ; https://www.cve.org/CVERecord?id=CVE-2026-24423 ; https://nvd.nist.gov/vuln/detail/CVE-2026-24423
CISA listing: www.cisa.gov/known-exploited-vulnerabilities-catalog

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-01-23 17:16:13 UTC
NVD last modified: 2026-02-06 16:45:15 UTC
NVD CVSS v3.1: 9.8 / 10 CRITICAL source: nvd@nist.gov
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploitability subscore: 3.9 / 10
Impact subscore: 5.9 / 10
EPSS score: 0.8203 (probability of exploitation in next 30 days)
EPSS percentile: 99.22% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-4273
Assigner: VulnCheck
Published: Jan 23, 2026, 4:53:34 PM
Updated: Mar 5, 2026, 1:30:27 AM
EUVD base score (CVSS 4.0): 9.3 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EUVD-reported EPSS: 81.9100
Vendors: SmarterTools
Products: SmarterMail (0 <100.0.9511)
Aliases: GHSA-7jpw-fm5p-f98m

ENISA description: SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the ConnectToHub API method. The attacker could point the SmarterMail to the malicious HTTP server, which serves the malicious OS command. This command will be executed by the vulnerable application.

EUVD references (3)

Affected products (1)

Vendor	Product	Versions	Platforms
SmarterTools	SmarterMail	`0` (affected)	—

Affected products — CPE 2.3 (1) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:a:smartertools:smartermail:*:*:*:*:*:*:*:*

Vendor references (3)

References embedded in the original CVE record by the assigning CNA.

https://www.smartertools.com/smartermail/release-notes/current release-notespatch
https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermail third-party-advisory
https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api third-party-advisory

MITRE references (1) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermail third-party-advisory

Web references (6)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

https://attackerkb.com/topics/CVE-2026-24423 rapid7:attackerkb.com
http://cwe.mitre.org/data/definitions/306.html rapid7:cwe.mitre.org
https://www.cve.org/CVERecord?id=CVE-2026-24423 rapid7:www.cve.org
https://www.smartertools.com/smartermail/release-notes/current rapid7:www.smartertools.com
https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api rapid7:www.vulncheck.com
https://nvd.nist.gov/vuln/detail/CVE-2026-24423 rapid7:nvd.nist.gov

NVD-tagged references (4)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermail disclosure@vulncheck.com Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24423 134c704f-9b21-4f2e-91b3-4a467353bcc0 US Government Resource
https://www.smartertools.com/smartermail/release-notes/current disclosure@vulncheck.com Release Notes
https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api disclosure@vulncheck.com Third Party Advisory

Indicators (2)

IOCs linked to the auto-promoted Threat row.

Type	Value	VirusTotal	Attached
cwe	`CWE-306`	no local data	2026-05-14 02:58 UTC
cve	`CVE-2026-24423`	no local data	2026-05-14 02:58 UTC

Remediations (9)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

120 Vulnerabilities Patched: Microsoft's May 2026 Patch Tuesday ...

web:www.secpod.com

The second Tuesday of May 2026 marked another major security update release from Microsoft, addressing a broad range of vulnerabilities across Windows, Microsoft Office, SharePoint, Dynamics 365, .NET, DNS Client, and other core enterprise components. While this month's Patch Tuesday did not include any actively exploited or publicly disclosed zero-day vulnerabilities, the release still ...

2026-05-14 17:20 UTC
Security Update Guide - Microsoft Security Response Center

web:msrc.microsoft.com

Security Update Guide - Microsoft Security Response Center

2026-05-14 17:20 UTC
May 12, 2026—Hotpatch KB5087423 (OS Build 26100.32772)

web:support.microsoft.com

This update applies to Windows Server 2025 Datacenter & Standard machines connected to Azure Arc. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates. To view ...

2026-05-14 17:20 UTC
Landing Page | ServiceNow Common Vulnerabilities & Exposures (CVE ...

web:support.servicenow.com

Overview The advisories below document publicly disclosed Common Vulnerabilities and Exposures ( CVEs ) in the Now Platform by ServiceNow. Because ServiceNow uses various methods to communicate vulnerability information, patches, and other fixes, customers should review family, security patch , and hotfix release notes, which are available at https://docs.servicenow.com, for a complete list of ...

2026-05-14 17:20 UTC
CISA warns of SmarterMail RCE flaw used in ransomware attacks

web:www.bleepingcomputer.com

The Cybersecurity & Infrastructure Security Agency (CISA) in the U.S. has issued a warning about CVE-2026-24423 , an unauthenticated remote code execution (RCE) flaw in SmarterMail that is used in ...

2026-05-14 17:20 UTC
Microsoft Patch Tuesday May 2026 - 120 Vulnerabilities Fixed, Including ...

web:cybersecuritynews.com

Microsoft's May 2026 Patch Tuesday lands with a heavy enterprise focus, fixing 120 vulnerabilities across Windows, Office, Azure, developer tools, and Microsoft 365 apps, including 29 remote code execution (RCE) flaws rated Critical.

2026-05-14 17:20 UTC
Dangerous Fake Microsoft Windows Update Confirmed—Do Not Download

web:www.forbes.com

As security researchers warn about a dangerous Microsoft Windows update that isn't legitimate, users must pay close attention to what they are actually downloading.

2026-05-14 17:20 UTC
Microsoft May 2026 Patch Tuesday Fixes 130+ Vulnerabilities ... - LinkedIn

web:www.linkedin.com

Microsoft has released its May 2026 Patch Tuesday security updates, addressing more than 130 vulnerabilities across its software ecosystem, including Windows, Microsoft Office, SharePoint Server ...

2026-05-14 17:20 UTC
CISA Required Action

CISA KEV

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Due date: 2026-02-26 Known ransomware campaign use: Known

2026-05-14 01:13 UTC

AI Forensic Analysis

Only Available for Registered Users. Sign in to view.

Raw JSON

The full cvelistV5 record. Download as CVE-2026-24423.json.

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