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

Added to the CISA Known Exploited Vulnerabilities catalog on 05 Feb 2026. Vendor: SmarterTools. Product: SmarterMail.

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.

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. (due 26 Feb 2026)