# CVE-2026-24423: SmarterMail - Authentication Bypass

> Live exploitation tracking for CVE-2026-24423 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2026-24423

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.3
- **Public exploit available:** No
- **Affected products:** SmarterTools SmarterMail
- **Weaknesses:** CWE-306 (Missing Authentication for Critical Function)
- **Tags:** mail

## 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.

## CrowdSec analysis

[CVE-2026-24423](https://euvd.enisa.europa.eu/vulnerability/CVE-2026-24423) is an unauthenticated remote code execution vulnerability in SmarterTools SmarterMail versions prior to build 9511. The vulnerability exists in the ConnectToHub API method, allowing attackers to point SmarterMail to a malicious HTTP server that serves a malicious OS command, which will be executed by the vulnerable application.

CrowdSec has been tracking this vulnerability and its exploits since 11th of February 2026.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2026-24423 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning.
Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2026-24423 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2026-24423 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Attackers can exploit this vulnerability by sending specially crafted HTTP requests to the ConnectToHub API method in SmarterMail. By directing SmarterMail to a malicious HTTP server that hosts a crafted OS command, attackers can trigger the execution of this command on the affected system without requiring any authentication.

## Timeline

- 2026-01-23: CVE Published. CVE-2026-24423 is published to NVD.
- 2026-02-05: CISA KEV. CVE-2026-24423 is added to the Known Exploited Vulnerabilities catalog by CISA.
- 2026-02-11: Rule Released. CrowdSec releases a rule to detect CVE-2026-24423 exploitation attempts against the CrowdSec Network.
- 2026-02-13: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2026-24423 for the first time.
- 2026-02-26: CISA Remediation Deadline. Expiration of the CISA remediation deadline as described in [BOD 22-01](https://www.cisa.gov/news-events/directives/bod-22-01-reducing-significant-risk-known-exploited-vulnerabilities).

## References

- https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api
- https://code-white.com/public-vulnerability-list/#systemadminsettingscontrollerconnecttohub-missing-authentication-in-smartermail
- https://www.smartertools.com/smartermail/release-notes/current
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-24423

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2026-24423) follows observed exploitation activity for CVE-2026-24423. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.