CVE-2026-24423 — SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability

Overview

SmarterTools SmarterMail contains a missing authentication for critical function vulnerability in the ConnectToHub API method. This could allow the attacker to point the SmarterMail instance to a malicious HTTP server which serves the malicious OS command and could lead to command execution.

Vulnerability details

CVE ID

CVE-2026-24423

Vulnerability

SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability

Vendor

SmarterTools

Affected products

SmarterTools: SmarterMail

Severity

HIGH

Exploitation status

Actively exploited in the wild (CISA KEV)

EPSS score

87.7% probability of exploitation in 30 days · 100th percentile

Published

2026-02-05

Remediation guidance

CVE-2026-24423 is in CISA's Known Exploited Vulnerabilities (KEV) catalog — U.S. federal civilian agencies are required to remediate it under Binding Operational Directive 22-01. Treat it as a priority for every environment.

Apply the vendor's official security update for SmarterTools the affected product as soon as possible. Where a patch is unavailable, apply vendor mitigations or isolate/segment exposed systems.

FIRST EPSS estimates a 87.7% probability that CVE-2026-24423 will be exploited within the next 30 days (100th percentile of all CVEs) — useful for risk-based patch sequencing.

Hunt for indicators of compromise tied to this vulnerability and confirm logging/EDR coverage on affected assets.

Authoritative references

• NVD — National Vulnerability Database
• MITRE CVE Record
• CISA Known Exploited Vulnerabilities Catalog
• FIRST EPSS — Exploit Prediction Scoring

Related actively-exploited CVEs — SmarterTools